CONFIDENTIAL

Bank of America Merrill Lynch 2015 Global Energy & Power Leveraged Finance Conference

June 2, 2015

2

DisclaimersEXPLANATORY NOTESummit Midstream Partners, LLC (“Summit Investments”) is a Delaware limited liability company and the predecessor for accounting purposes (the“Predecessor”) of Summit Midstream Partners, LP (“SMLP”). The accompanying financial and operating information and related notes include the assets,liabilities and results of operations of Summit Investments prior to Summit Investments’ contribution of all of the limited liability company interests in SummitMidstream Holdings, LLC to SMLP in connection with SMLP’s initial public offering (“IPO”). The financial and operating information included in this presentationreflect the Predecessor financial statements, which are based on the historical ownership percentages of the operations that were contributed to SMLP by EnergyCapital Partners II, LLC and its parallel and co-investment funds and GE Energy Financial Services, Inc. (collectively the "Sponsors") prior to the IPO. The effectsof the IPO and related equity transfers occurring in October 2012 are reflected in this financial information subsequent to the IPO. The results of the Predecessorprior to the IPO may not be indicative of SMLP’s future financial results.

FORWARD LOOKING STATEMENTSThis presentation includes certain statements, estimates and projections provided by Summit with respect to its anticipated future performance. These “forward-looking” statements appear in a number of places in this presentation and include, but are not limited to, statements regarding Summit’s plans, intentions, beliefs,expectations and assumptions, as well as other statements that are not historical facts. Generally, these statements can be identified by the use of forward-looking terminology including “will,” “may,” “believe,” “expect,” “anticipate,” “estimate,” “continue,” or other similar words. When considering these “forward-looking” statements, you should keep in mind that a number of factors that are beyond Summit’s control could cause actual results to differ materially from theresults contemplated by any such forward-looking statements including, but not limited to, the following risks and uncertainties: fluctuations in oil, natural gas andNGL prices; the extent and quality of natural gas volumes produced within proximity of Summit’s assets; failure or delays by Summit’s customers in achievingexpected production in their natural gas projects; competitive conditions in Summit’s industry and their impact on Summit’s ability to connect natural gas suppliesto its gathering and processing assets or systems; actions or inactions taken or nonperformance by third parties, including suppliers, contractors, operators,processors, and shippers; Summit’s ability to successfully integrate recently acquired assets; operating hazards, natural disasters, weather-related delays,casualty losses and other matters beyond Summit’s control; Summit’s ability to control the costs of construction, including costs of materials, labor and right-of-way and other factors that may impact Summit’s ability to complete projects within budget and on schedule; and the effects of existing and future laws andgovernmental regulations, including environmental requirements on Summit’s business or operations. In addition, any determination by Summit Investments tooffer any of its assets, including its interest in Ohio Gathering, to SMLP will be made in Summit Investments' sole discretion and will in any event be subject to anumber of factors, including, but not limited to, the ability to reach agreement on acceptable terms, the approval of the conflicts committee of SMLP (ifappropriate), prevailing conditions and outlook in the natural gas and NGL industries and markets, and SMLP's ability to obtain financing on acceptable terms,from the capital markets or other sources. All of the forward-looking statements made in this document are qualified by these cautionary statements, and Summitcannot assure you that actual results or developments that Summit anticipates will be realized or, even if substantially realized, will have the expectedconsequences to, or effect on, Summit or its business or operations.

Although the expectations in the forward-looking statements are based on Summit’s current beliefs and expectations, caution should be taken not to place unduereliance on any such forward-looking statements because such statements speak only as of the date hereof. Summit expressly disclaims any obligation to updateor revise any forward-looking statements, whether as a result of new information, future events or otherwise.

Furthermore, the “forward-looking” statements reflect various assumptions by Summit concerning anticipated results, which assumptions may or may not prove tobe correct. Neither Summit nor any of its affiliates has undertaken any independent investigation or evaluation of such assumptions to determine theirreasonableness.

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$0.400 $0.410 $0.420 $0.435 $0.460 $0.480 $0.500 $0.520 $0.540 $0.560 $0.565

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MQD 4Q'12 1Q'13 2Q'13 3Q'13 4Q'13 1Q'14 2Q'14 3Q'14 4Q'14 1Q'15

$ / Unit

(40.0%)

0.0%

40.0%

80.0%

120.0%

160.0%

200.0%

240.0%

Sep-

12

Oct

-12

Nov

-12

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-12

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13

Feb-

13

Mar

-13

Apr-1

3

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-13

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SMLP S&P 500 Alerian MLP Index

Summit Midstream Partners, LP Overview

Total Return Analysis – Since SMLP IPO(1)

Distribution Per LP UnitGeneral Overview

SMLP IPO:$20.00 / Unit

93.1%

55.1%25.7%

(1) As of May 29, 2015, including the May 2015 issuance of 7.475 million common units and 154,049 general partner units.(2) 2015 Adj. EBITDA guidance updated on May 6, 2015. Guidance excludes the impact of additional potential drop downs from Summit Investments.

(in thousands, except per unit information)

Ticker SMLPExchange NYSE

Current SMLP Price Per Unit(1) 33.63$ Total Units Outstanding(1) 67,735

Market Capitalization 2,277,929$

1Q 2015 Distribution Per Unit 0.565$ Annualized 1Q 2015 Distribution Per Unit 2.260$ Current Yield 6.72%

2015 Adjusted EBITDA Guidance(2) $210 - $225 million

4

SMLP – Proven Track Record of Growth

(1) Summit Investments is not obligated to sell assets to SMLP and SMLP is not obligated to purchase such assets.

Over $1 Billion of Drop Downs and Third Party M&A at SMLP Since IPO

Identified Future Growth Catalysts

Drop downs from Summit Investments(1)

Organic growth in Utica and Williston basins

Additional organic growth in Utica, Bakken and around existing assets

Third party acquisitions

$0.400 $0.410 $0.420 $0.435 $0.460 $0.480 $0.500 $0.520 $0.540 $0.560 $0.565

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MQD 4Q '12 1Q '13 2Q '13 3Q '13 4Q '13 1Q '14 2Q '14 3Q '14 4Q '14 1Q '15

$ / Unit

Potential Additional Growth Catalysts

10 Consecutive Quarters of Distribution Growth Per Unit

$0

$100

$200

$300

$400

$500

2013 2014 2015 YTD

$ in

Mill

ions

Bison Drop$250mm

Mountaineer Acquisition

$210mm

Red Rock Drop

$305mm

Polar & Divide Drop

$290mm

Lonestar Acquisition

$11mm

5

Peer Valuation Analysis(1)

SMLP Continues to Be Undervalued Relative to Many of Its Peers

(1) As of May 29, 2015. Peer data from Barclays Capital research.(2) SMLP performed a linear regression analysis on gathering and processing and drop down peers based on three year distribution growth and distribution yield

At current trading levels, SMLP’s distribution yield implies a 4.8% three year growth rate for SMLP(2)

Three year growth rates of 7.5% to 15.0% imply distribution yields of 6.2% to 4.6%, respectively

2.5%2.9%

4.2% 4.2% 4.4% 4.4% 4.6%4.8% 5.0% 5.1%

5.6% 5.6%

6.1% 6.2%

6.7%

7.6%

8.3%

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

AM EQM WES TEP CNNX RMP SMLP -15%

ImpliedGrowth

TLLP RRMS SMLP -12.5%ImpliedGrowth

MWE SMLP -10%

ImpliedGrowth

ENLK SMLP -7.5%

ImpliedGrowth

SMLP -Current

Yield

NGLS DPM

Dis

trib

utio

n Yi

eld

%

5.1% Avg. Peer Yield

Three Year Growth

Rate

Implied Dist. Yield

Implied SMLP

Unit Price%

Appreciation

4.8% 6.72% $33.63 n/a7.5% 6.15% $36.72 9.2%10.0% 5.62% $40.20 19.5%12.5% 5.09% $44.40 32.0%15.0% 4.56% $49.58 47.4%

6

Summit Organizational Structure

Public Unit Holders

54.1% LP Interest

$600MM Senior Notes

$700MM RevolverSummit Midstream

Finance Corp.

100%

Summit Midstream Partners, LLC(“Summit Investments”)

Summit Midstream Partners Holdings, LLC(“SMP Holdings”)

100%

2.0% GP Interest / IDRs43.9% LP Interest

– 5.3MM Common Units– 24.4MM Sub Units

Summit Midstream Partners, LP (NYSE: SMLP)

Summit Midstream Holdings, LLC PUBLIC

COMPANY

Marcellus ShalePiceance BasinBarnett Shale Williston Basin

Rockies‒ Tioga Midstream (Williston)‒ Blacktail Gathering (Williston)‒ Niobrara G&P (DJ)

Utica‒ Summit Midstream Utica‒ Ohio Gathering Co. (40%)‒ Ohio Condensate Co. (40%)

7

SMLP Asset MapIncreased Scale & Geographic Diversity Across Four Basins

Polar & DivideConstructed Under Construction

8

97%+ of revenue is fee-based 3.7 Tcf of remaining MVCs through 2026 provide downside protection Contracts provide for stable cash flow and limited direct commodity price exposure

Geographically diverse operating footprint with over 1.6 million acres dedicated Active across four basins including the Marcellus, Williston, Barnett and the Piceance Natural gas, NGL, produced water and crude oil gathering services

Investing ~$1.9 billion at Summit Investments, primarily in Utica & Williston – GP assets are 100% fee based Average of $400-$800 million of drop downs per year through 2017 support long term distribution growth Drop downs provide SMLP with scale and further diversification by basin, commodity, customer and service

1Q 2015 distribution coverage ratio of 1.01x 3.9x leverage ratio and approximately $442 million of pro forma revolver liquidity as of 3/31/15 Access to Sponsor equity; Sponsor has proven track record of equity capital support of the Summit enterprise

SMLP Investment Considerations & Operating Statistics(1)

Growth-oriented midstream MLP focused on natural gas, crude oil and produced water gathering

As of March 31, 2015 Marcellus Williston: Natural Gas

Williston: Liquids Barnett Piceance Total

Miles of Pipeline In Service 49 392 298 128 1,779 2,646

Average Daily Gas Volumes (MMcf/d)(1) 547 18 -- 403 615 1,583

Operating Capacity (MMcf/d) 1,050 26 -- 480 1,153 2,709

Average Daily Liquids Volumes (Bbl/d)(1) -- -- 48,112 -- -- 48,112

Operating Capacity (Bbl/d) -- -- 80,000 -- -- 80,000

1Q 2015 Pro Forma SMLP Operating Data

SMLP Investment Considerations

(1) For the quarter ended March 31,2015. Pro forma for May 2015 Polar & Divide drop down.

Fee-BasedContract Portfolio

Diversified Operations

Strong Capital Position

Visible Growth From Drop Downs

9

Polar & Divide Drop Down OverviewAsset Details

$290 million drop down transaction executed in May 2015

Consists of more than 295 miles of crude oil and produced water pipeline, spanning throughout Williams and Divide counties in North Dakota

Underpinned by long-term, fee-based gathering agreements with leading Williston producers

‒ Downside protection via rate redeterminations

Four growth projects currently under development:

Whiting Expansion: Expansion agreement, executed in 2Q 2014, to connect 64 new pad sites

Zavanna Expansion: Expansion agreement, executed in 4Q 2014, to connect 23 new pad sites

Little Muddy Interconnect: 15 miles of 10” pipeline, crude oil tankage, and an interconnect into Enbridge’s North Dakota system, expected commissioning in 3Q 2015

Stampede Lateral: 46 mile crude oil pipeline from the Divide Station to Global Partners’ Basin Columbus rail terminal for delivery to east coast markets

Based on 2016 projected EBITDA, SMLP is acquiring the Polar & Divide system, including approximately $75 million of growth capital expenditures through the fourth quarter of 2016, at a 7.8x acquisition multiple

Polar & Divide Asset Map

Polar & DividePolar & Divide under construction

Stampede Lateral

Global Partners’ Basin Columbus

Rail Terminal

10

Fee-Based(3)

97%

Variable 3%

SMLP’s Current & Projected Business Profile

Revenue Composition

Drop down strategy will further diversify SMLP geographically while enhancing its core focus on fee-based revenue

Adjusted EBITDA Composition

Fee-Based(3)

97%

Variable 3%

Fee-Based(3)

98%

Variable 2%

Barnett

Piceance

Marcellus

Williston Barnett

Piceance

MarcellusUtica

Williston18%

22%

40%

19%

43%

28%

(1) Pro forma to include Polar & Divide drop down.(2) Pro forma for the drop down of all existing Summit Investments assets to SMLP.(3) Excludes CO2 revenue, electricity revenue and favorable and unfavorable amortization of contracts, and other reimbursables, which are pass-through items. Includes fuel retainage revenue which is used to offset compression fuel expense at DFW.

2015E(1) 2019E(2)

2015E(1) 2019E(2)

12%

56%

32%

2012 at IPO

2012 at IPO

Barnett

Piceance

48%52% 10%

13%

7%

11

Differentiated Contract Portfolio with Significant MVC Underpinning

SMLP Contract Portfolio Overview

Primarily long-term and fee-based contracts for natural gas,crude oil and produced water gathering

Weighted-average remaining contract life of 9.2 years

Remaining natural gas MVCs total 3.7 Tcf and run through 2026

– MVCs average 1,212 MMcf/d through 2019

Over 1.6 million acres contractually dedicated in some of thefastest growing production basins in North America

A substantial majority of Polar & Divide’s volume throughput issubject to rate redetermination mechanisms

Segment

Acreage Dedication (net acres)

2015E Avg. Fee(2)

(per Mcf)

2015E Avg. Fee(2)

(per Bbl)

Total Remaining

Commitment (Bcf)(3)

Avg. Daily MVCs Through 2019 (MMcf/d)(3)

1Q 2015 Avg. Daily

Throughput(MMcf/d)

1Q 2015 Avg. Daily

Throughput(Mbbl/d)

Wtd. Avg. Remaining Contract Life(3,4)

PiceanceBasin 670,960(5) $0.52 -- 2,095 724 615 -- 9.7 years

Barnett Shale 108,314 $0.61 -- 186 102 403 -- 4.5 years

Williston Basin(1) 869,120 $2.98 $1.76 19 10 18 48 5.3 years

Marcellus Shale(6) n/a n/a -- n/a n/a 547 -- n/a

Wtd. Avg. / Total 1,648,394 $0.45 $1.76 3,705 1,212 1,583 48 9.2 years

(1) Includes Polar & Divide drop down. Excludes MVCs associated with Polar & Divide assets due to confidentiality. (2) Estimated for the year ended December 31, 2015. (3) As of March 31,2015. (4) Weighted averages based on Total Remaining Minimum Revenue (Total Remaining MVCs x Average Rate).(5) For Red Rock, includes acreage dedications for the top 10 largest customers by throughput.(6) Contract terms excluded for confidentiality purposes.

1,583

1,212

1Q 2015 Throughput MVCs Through 20190

200400600800

1,0001,2001,4001,600

MM

cf/d

Avg. Gas MVCs Through 2019 = 77% of 1Q 2015 Throughput

Summit Investments Overview

13

Operating Area

StatusSystem

Mileage(1)

Total System

Capacity(1)

Investment Through 2014

Investment in 2015

Investment From

2016-2019

Expected Total Investment

Through 2019(2)

Utica In Service & Under Development ~ 700 miles Confidential ~ $725 ~ $225 ~ $625 ~ $1,575

Williston In Service & Under Development

~ 320 miles oil & water

~ 60 miles nat gas

115 Mbbl/d oil & water14 MMcf/d

nat gas

~ $120 ~ $60 ~ $35 ~ $215

DJ In Service ~ 90 miles15 MMcf/d

processing plant~ $70 ~ $5 ~ $5 ~ $80

Total Summit Investments ~ $915 ~ $290 ~ $665 ~ $1,870

$217.5(3)

$500 +

$0

$100

$200

$300

$400

$500

2015 2016 2017 2018 2019

Adjusted EBITDA ($MM)

Drop Downs From Summit Investments To Drive Growth For SMLP

SMLP’s relationship with Summit Investments provides it with long-term, visible growth

Illustrative Example: Drop Downs + SMLP Organic Growth = Top Tier Growth

(1) Pro forma for full system build out.(2) Includes acquisition capital and estimated development capital through 2019.(3) For 2015, assumes mid-point of adjusted EBITDA guidance of $210 million to $225 million. Assumes 5.0% annual EBITDA growth of base business.

Organic growth capital invested

at 6.0x to 8.0x EBITDA

More than $240 million of

incremental EBITDA

($ in millions)

14

Summit Utica & Ohio Gathering – Expanding Utica Footprint

Overview Summit Investments invested approximately $725 million in its

Utica Shale development in 2014– Expect to invest an additional $850 million on identified

growth projects through 2019 Excludes additional growth opportunities in the

region that are currently being evaluated Estimate that Summit Investments’ Utica activities will

represent ~ 40% of SMLP adj. EBITDA by 2019

Ohio Gathering: Summit Investments owns a 40% interest in Utica Shale

natural gas gathering systems and condensate stabilization facility with MarkWest Utica EMG

Multi-billion dollar capex program associated with development of:

– Liquids-rich gas gathering system– Dry gas gathering system – Condensate stabilization facility

Development underpinned by Gulfport Energy and American Energy Utica (“AEU”)

Summit Utica: Wholly-owned and operated natural gas gathering system in

the dry gas window of southeastern Ohio $400 million development which will consist of 115 miles of

pipeline with 500 MMcf/d of initial throughput capacity Development underpinned by XTO Energy and AEU

Condensate

Wet GasDry Gas

Summit Investments is building a dominant footprint in the Utica Shale –the highest return shale play in the United States(1)

Ohio Gathering Focus Area

Ohio Gathering Dry Gas System

23,000 Bbl/d Condensate Stabilization Facility

Summit Utica Focus Area

(1) Credit Suisse; January 2015. Analysis based on NYMEX natural gas futures strip avg. of $3.00 and WTI oil futures strip avg. of $70.00

Asset Footprint

15

DJ AssetsWilliston Assets

Tioga / Blacktail / Hereford – Sizable Rockies Footprint

Tioga Midstream

‒ Crude oil, produced water, and associated natural gas gathering for Hess

‒ Executed in 2Q 2014 – multi-year development underway

‒ 117,560 acres dedicated to the system

Blacktail Gathering

‒ Approx. 150 miles of crude oil and produced water pipeline

‒ 45,000 bbl/d of crude oil capacity and 45,000 bbl/d of produced water capacity

Hereford Plant

Codell Play

WeldCounty

LaramieCounty

CO

WY

NE

Colorado

Blacktail Gathering

Tioga Midstream

Niobrara G&P

‒ Commissioned in September 2013 and subsequently expanded in September 2014

‒ Niobrara G&P is underpinned by a long-term, fee-based gathering and processing agreement with EOG Resources

‒ Niobrara G&P is well positioned to benefit from further growth with EOG Resources relative to its recently announced CodellPlay

EOG Resources constructed a 40 MMcf/d pipeline to access the Hereford Processing Plant and is currently delivering liquids-rich natural gas from its “Fairway Play” for processing

EOG Pipeline

SMLP Asset Overview

17

Marcellus Shale

Asset Summary

High-pressure gas gathering and compression assets located in the rich gas window of the Marcellus Shale play

Map of Mountaineer Assets

MarkWest Energy Partners, L.P.’s Sherwood Complex

Sherwood I – V – 1,000 MMcf/d – OperationalSherwood VI – 200 MMcf/d – 2Q15Sherwood VII – 200 MMcf/d – 2Q16De-ethanization – 40,000 Bbl/d – 4Q15

Asset Mountaineer Midstream

Reportable Segment Marcellus Shale

1Q 2015 Throughput 547 MMcf/d

Throughput Capacity 1,050 MMcf/d

Basin Served Appalachian

Underlying Formation Marcellus Shale

Counties Served Doddridge & Harrison counties, WV

Services Provided Natural Gas Gathering

Primary Customers Antero Resources

Delivery Point MWE's Sherwood Gas Processing Facility

Miles of Pipeline 49 miles

Revenue(1) 100% Fee-Based Revenue

Avg. Gathering Fee(2) Confidential

Acreage Dedication n/a

Aggregate Remaining MVC(2) Confidential

Avg. Daily MVC Through 2019(2) Confidential

Remaining Contract Life(2) Confidential(1) Estimated for the year ending December 31, 2015.(2) Contract terms excluded for confidentiality purposes.

18

Williston Basin

Asset Summary

Crude oil, produced water, and associated natural gas gathering in the Bakken Shale Play

Map of Williston Assets

Stampede Lateral

Bison

Polar & Divide

Polar & Divide

Constructed

Under Construction

Reportable Segment Williston BasinRevenue(1) ~ 90% Fee-Based RevenueAcreage Dedication 869,120 acresAggregate Remaining MVC(2) 19 BcfAvg. Daily Gas MVC Through 2019 10 MMcf/dRemaining Contract Life(3) 5.3 Years

Asset Bison Midstream1Q 2015 Natural Gas Throughput 18 MMcf/dNatural Gas Throughput Capacity 26 MMcf/dAvg. Gathering Fee(1) $2.98 / McfBasin Served WillistonUnderlying Formation Bakken & Three ForksCounties Served Mountrail & Burke counties, NDPrimary Customers EOG, Oasis, Hunt, HessMiles of Pipeline 392 milesDelivery Points Aux Sable's Conditioning Plant in Palermo, ND

Asset Polar & Divide1Q 2015 Liquids Throughput 48 Mbbl/dLiquids Throughput Capacity 80 Mbbl/dAvg. Gathering Fee(1) $1.76 / BblBasin Served WillistonUnderlying Formation Bakken & Three ForksCounties Served Williams & Divide counties, NDPrimary Customers Whiting, SM Energy, ZavannaMiles of Pipeline 298 milesDelivery Points COLT Hub, Little Muddy (Enbridge)(4), Basin Columbus(4)

(1) Estimated for the year ending December 31, 2015.(2) As of March 31, 2015.(3) Weighted avg based on Total Remaining Minimum Revenue (Total Remaining MVC x Avg. Fee).(4) Access to delivery points expected to be in service by the end of 2015

Associated Natural Gas Gathering

Crude Oil & Water Gathering

19

Barnett Shale

Asset Summary

Natural gas gathering in the “core of the core” of the Barnett

Map of DFW Midstream

Asset DFW Midstream

Reportable Segment Barnett Shale

1Q 2015 Throughput 403 MMcf/d

Throughput Capacity 480 MMcf/d

Basin Served Ft. Worth

Underlying Formation Barnett

Primary Counties Served Tarrant & Dallas counties, TX

Services Provided Natural Gas Gathering & Treating

Primary Customers Chesapeake, Enervest, XTO, Vantage & Beacon

Delivery Points Line X, Old Ocean Pipeline, Trinity River Lateral

Miles of Pipeline 128 miles

Compression Horsepower 66,100

Revenue(1) 100% Fee-Based Revenue

Avg. Gathering Fee(1) $0.61 / Mcf

Acreage Dedication 108,314 acres

Aggregate Remaining MVC(2) 186 Bcf

Avg. Daily MVC Through 2019 102 MMcf/d

Remaining Contract Life(3) 4.5 Years(1) Estimated for the year ending December 31, 2015.(2) As of March 31, 2015.(3) Weighted avg based on Total Remaining Minimum Revenue (Total Remaining MVC x Avg. Fee).

20

Piceance Basin

Asset Summary

Positioned in the core of the Piceance Basin with exposure to the liquids-richMesaverde formation as well as the emerging Mancos & Niobrara formations

Map of Grand River

Asset Grand River

Reportable Segment Piceance Basin

1Q 2015 Throughput 615 MMcf/d

Throughput Capacity 1,153 MMcf/d

Basins Served Piceance

Underlying Formations Mesaverde, Mancos & Niobrara

Primary Counties Served Garfield, Mesa & Rio Blanco counties, CO

Services Provided Natural Gas Gathering & Processing

Primary Customers Encana, WPX, Vanguard, Ursa, Black Hills

Piceance Delivery Points Meeker, Northwest Pipeline, TransColorado Pipeline

Miles of Pipeline 1,779 miles

Revenue(1) 90%+ Fee-Based Revenue

Avg. Gathering Fee(1) $0.52 / Mcf

Acreage Dedication 670,960 acres

Aggregate Remaining MVC(2) 2,095 Bcf

Avg. Daily MVC Through 2019 724 MMcf/d

Remaining Contract Life(3) 9.7 Years(1) Estimated for the year ending December 31, 2015.(2) As of March 31, 2015.(3) Weighted avg based on Total Remaining Minimum Revenue (Total Remaining MVC x Avg. Fee).

SMLP Financial Overview

22

Conservative Financial Strategy

Strong balance sheet and liquidity enables SMLP to execute its growth strategy

Targeting long-term leverage ratio of 3.5x – 4.0x

$442 million of pro forma availability at March 31, 2015 under $700million revolver

‒ Additional liquidity available from $200 million accordion

1Q 2015 distribution of $0.565 per unit

– Increased 1Q 2015 distribution to LP unitholders by 13.0%over 1Q 2015 and 0.9% over 4Q 2014

– Generated a distribution coverage ratio of 1.01x for 1Q 2015

$258

$442

$0

$200

$400

$600

$800

2015 2016 2017 2018 2019 2020 2021 2022

$ in

Milli

ons

Revolving Credit

Facility

7.50% Senior Notes B/B3

5.50% Senior Notes B/B3

Long-Term Debt Maturities$442 million of pro forma availability at 3/31/15 under

$700 million revolver

Actual Pro Forma($s in 000s) Mar-15 Adjustments Mar-15

Cash and Cash Equivalents $13,096 (750) $12,346

Total Debt:Revolving Credit Facility (Due Nov. 2018) 196,000 62,382 258,3827.50% Senior Notes (Due July 2021) 300,000 - 300,0005.50% Senior Notes (Due August 2022) 300,000 - 300,000

Total Debt 796,000 62,382 858,382

Partners' Capital:Common Limited Partner Capital 630,241 222,131 852,372Subordinated Limited Partner Capital 279,524 - 279,524General Partner Interests 24,100 4,737 28,837

Total Partners' Capital 933,865 226,868 1,160,733

Total Capitalization $1,729,865 $289,250 $2,019,115

Distribution Coverage Ratio (Annual) 1.01x

Covenant Compliance EBITDA (LTM) 200,095 15,500 215,595

Credit MetricsDebt / EBITDA 3.9x 3.9xDebt / Total Capitalization 46.0% 42.5%

Committed LiquidityCash & Cash Equivalents 13,096 (750) 12,346Revolver Availability 504,000 (62,382) 441,618

Total Liquidity $517,096 ($63,132) $453,964

23

SMLP Financial Profile – As Reported

Adjusted EBITDA(2)

Capital Expenditures(1)

Adjusted Distributable Cash Flow

Volume Gathered

136

431

952 1,138

1,418 1,583

0

400

800

1,200

1,600

2010 2011 2012 2013 2014 ThreeMos.

Ended3/31/15

MMcf/d

$154

$78 $77$109

$128

$12$0

$40

$80

$120

$160

$200

2010 2011 2012 2013 2014 ThreeMos.

Ended3/31/15

$MM

$12

$54

$93

$131 $141

$36

$0

$30

$60

$90

$120

$150

2010 2011 2012 2013 2014 Three Mos.Ended3/31/15

$MM

$12

$57

$106

$165$194

$50

$0

$50

$100

$150

$200

2010 2011 2012 2013 2014 Three Mos.Ended3/31/15

$MM

(1) Excludes acquisition capital expenditures.(2) EBITDA adjustments include adjustments related to MVC shortfall payments and unit-based compensation expense. Adjusted EBITDA includes transaction costs. These unusual and non-recurring expenses are settled in cash. For a reconciliation of adjusted

EBITDA and adjusted distributable cash flow to their nearest comparable GAAP financial measures, please see “Non-GAAP Reconciliations.”

24

SMLP – 2015 Financial Guidance

Actual Actual Actual Guidance RangeFY 2015(3)

($ in millions)

Year Ended 2012

Year Ended 2013

Year Ended 2014 Low High

Adjusted EBITDA $105.9 $164.8 $193.8 $210.0 $225.0

LP Distribution Growth(1,2) n/a 20.0% 16.7% 7.0% 8.0%

Growth Capex $71.2 $94.5 $112.4 $106.0 $122.0

Maintenance Capex $6.1 $14.9 $15.9 $14.0 $18.0

Total Capex $77.3 $109.4 $128.3 $120.0 $140.0

(1) Distribution growth for the year ended December 31, 2013 is relative to SMLP’s minimum quarterly distribution of $0.40 / unit.(2) Distribution growth for the year ended December 31, 2014 is for the fourth quarter of 2014 relative to the fourth quarter of 2013 distribution of $0.48 / unit paid on February 14, 2014.(3) As updated on May 6, 2015.

SMLP Non-GAAP Reconciliations

26

SMLP Non-GAAP Reconciliations

(1) Includes transaction costs. These unusual expenses are settled in cash.(2) The amortization of favorable and unfavorable contracts relates to gas gathering agreements that were deemed to be above or below market at the acquisition of the DFW Midstream system. We amortize these contracts on a units-of-production basis over the

life of the applicable contract. The life of the contract is the period over which the contract is expected to contribute directly or indirectly to our future cash flows. (3) Adjustments related to MVC shortfall payments account for (i) the net increases or decreases in deferred revenue for MVC shortfall payments and (ii) our inclusion of future expected annual MVC shortfall payments. (4) In connection with the decline in commodity prices during the fourth quarter of 2014, we reevaluated the carrying value, including goodwill, of the Bison Midstream gathering system and recognized a goodwill impairment for the decline in the fair value of the

underlying reporting unit relative to its carrying value.(5) During the fourth quarter of 2014, we reviewed certain property, plant and equipment balances associated with a compressor station project on our DFW Midstream system that was terminated and wrote off approximately $5.5 million of costs. The impact of

this write off is reflected in long-lived asset impairment.(6) During the fourth quarter of 2014, we identified and wrote off certain balances previously recognized in connection with the purchase accounting for the Legacy Grand River system. This write off was recognized as a $1.2 million increase to other income.

($s in 000s) 2015 2014 2014 2013 2012 2011 2010

Net Income(1) $1,667 $6,373 ($21,164) $53,304 $42,997 $37,951 $8,172

Add:

Interest expense 12,118 7,144 40,159 19,173 12,766 3,054 0

Income tax expense 177 159 631 729 682 695 124

Depreciation and amortization 22,143 19,642 82,990 69,962 36,674 11,367 3,874

Amortization of favorable and unfavorable contracts(2) 251 226 944 1,032 192 308 215

Less:

Interest income 1 1 4 5 9 12 32

EBITDA(1) $36,355 $33,543 $103,556 $144,195 $93,302 $53,363 $12,353

Add:

Unit-based compensation 1,312 1,063 4,696 3,506 1,876 3,440 0

Adjustments related to MVC shortfall payments(3) 12,340 12,013 26,565 17,025 10,768 0 0

Loss on asset sales 0 0 442 113 0 0 0

Goodwill impairment(4) 0 0 54,199 0 0 0 0

Long-lived asset impairment(5) 0 0 5,505 0 0 0 0

Less:

Impact of purchase price adjustments(6) 0 0 1,185 0 0 0 0

Adjusted EBITDA(1) $50,007 $46,619 $193,778 $164,839 $105,946 $56,803 $12,353

Three Months Ended March 31, Year Ended December 31,

27

SMLP Financial Performance

(1) Includes transaction costs. These unusual expenses are settled in cash.(2) Adjustments related to MVC shortfall payments account for (i) the net increases or decreases in deferred revenue for MVC shortfall payments and (ii) our inclusion of future expected annual MVC shortfall payments. (3) Senior notes interest expense represents interest expense recognized and accrued during the period. Interest on the $300 million 5.5% senior notes is paid in cash semi-annually in arrears on February 15 and August 15 until maturity in August 2022.

Interest on the $300 million 7.5% senior notes due 2021 is paid in cash semi-annually in arrears on January 1 and July 1 until maturity July 2021.(4) Expenses associated with SMLP’s obligations under Section 404 of the Sarbanes-Oxley Act of 2002 and Summit’s adoption of the 2013 Internal Control-Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway

Commission (“COSO 2013”). These first-year COSO 2013 expenses are not expected to be incurred subsequent to completion of the 2014 integrated audit in March 2015.

Three Months Ended March 31, Variance

($s in 000s) 2015 2014 $ %

Distributable Cash Flow:

EBITDA(1) $36,355 $33,543 $2,812 8.4%

Add:

Unit-based compensation 1,312 1,063 249 23.4%

Adjustments related to MVC shortfall payments(2) 12,340 12,013 327 2.7%

Adjusted EBITDA(1) $50,007 $46,619 $3,388 7.3%

Add:

Interest income 1 1 0 0.0%

Less:

Cash interest paid 22,812 14,308 8,504 59.4%

Senior notes interest expense(3) (11,171) (6,500) (4,671) 71.9%

Cash taxes paid 0 0 0 n/a

Maintenance capital expenditures 2,465 5,079 (2,614) (51.5%)

Distributable cash flow $35,902 $33,733 $2,169 6.4%

Add:

Transaction costs(1) 0 537 (537) (100.0%)

Regulatory compliance costs(4) 103 0 103 n/a

Adjusted distributable cash flow $36,005 $34,270 $1,735 5.1%

Distributions declared $35,526 $30,384 $5,142 16.9%

Distribution coverage ratio 1.01x

28

SMLP – Segment Adjusted EBITDA

($s in 000s) 2015 2014

Segment Adjusted EBITDA

Marcellus Shale $6,535 $3,883

Williston Basin 5,333 4,676

Barnett Shale 16,760 15,034

Piceance Basin 27,236 25,581

Total reportable segment adjusted EBITDA $55,864 $49,174

Allocated corporate expenses (5,857) (2,555)

Total Adjusted EBITDA $50,007 $46,619

Three Months Ended March 31,

Appendix – Additional Information

30

Mountaineer Midstream – Strategic Position in Core of Marcellus ShaleMap of Marcellus ShaleMarcellus Shale Overview

Mountaineer provides high-pressure gathering and compression services for Antero Resources in the northern West Virginia region of the Marcellus Shale

Currently 20 rigs operating in West Virginia with 9, or 45%, operating in Doddridge and Harrison counties

Antero is currently operating 7 drilling rigs in the Marcellus Shale Play

– Antero has completed over 400 horizontal wells to date

Antero has indicated that wells in their acreage have average EURs of ~2.0 Bcf / 1,000 ft. lateral

– Antero has averaged 7,500 ft. laterals in the Marcellus

Sources: Antero Investor presentation, Baker Hughes, Drilling Info.

Representative Well Economics Antero estimates 1,638 gross horizontal drilling locations in its

1,100 to 1,275 Btu window

– 15% to 30% ROR based on December 2014 strip pricing

BTU Content Well Cost ($MM) EUR (Bcfe) F&D ($/Mcf) Pre-Tax ROR

1,050 $11.2 15.3 $0.90 15%

1,150 $11.2 16.8 $0.82 15%

1,250 $11.2 18.8 $0.73 30%

Mountaineer Midstream

31

Mountaineer Midstream – Asset Overview

Assets commissioned in 4Q 2012

Long-term, fee-based gathering and compression contract with Antero

Significant volume ramp underway

Mountaineer gas is dedicated to MarkWest’s Sherwood Processing Complex (“Sherwood”)

– Sherwood processing capacity currently at 1.0 Bcf/d and is expected to increase to 1.4 Bcf/d by 2Q 2016

– Volume throughput increases on Mountaineer expected to track increases in Sherwood processing capacity

Asset Details

0 80 96 133 135 197 286 366 416 459 547

0200

400600800

1,0001,200

3Q'12 4Q'12 1Q'13 2Q'13 3Q'13 4Q'13 1Q'14 2Q'14 3Q'14 4Q'14 1Q'15

MMcf/d

Mountaineer Throughput Sherwood Processing Capacity

Mountaineer Quarterly Throughput

49 miles of high-pressure gas gathering and compression assets located in the rich gas window of the Marcellus Shale Play

Map of Mountaineer Assets

MarkWest Energy Partners, L.P.’sSherwood Complex

Sherwood I – V – 1,000 MMcf/d – OperationalSherwood VI – 200 MMcf/d – 2Q15Sherwood VII – 200 MMcf/d – 2Q16De-ethanization – 40,000 Bbl/d – 4Q15

32

Strategic Position in Growing Williston Basin

Sources: Baker Hughes, Drilling Info, Bentek Energy, North Dakota Oil and Gas Division.

Williston Basin Overview

0

20

40

60

80

100

120

140

0

200

400

600

800

1,000

1,200

1,400

1,600

Mar-06 Mar-07 Mar-08 Mar-09 Mar-10 Mar-11 Mar-12 Mar-13 Mar-14 Mar-15

Mcf

/d p

er W

ell

MM

cf/d

MMcf/d Sold MMcf/d Flared Avg. Well Productivity

Currently over 79 rigs operating in the Williston Basin

– Targeting crude oil production from the Bakken and Three Forks shale formations

Polar & Divide gathers crude oil and produced water

– Since September 2011, crude oil production in North Dakota has grown from approximately 464,000 Bbl/d to over 1,191,000 Bbl/d as of March 2015

Bison gathers and compresses associated natural gas

Associated natural gas production in North Dakota has grown from approximately 482 MMcf/d in September 2011 to 1.5 Bcf/d in March 2015

– Approximately 25% of natural gas produced in North Dakota is currently being flared as of March 2015

North Dakota Natural Gas Production

Map of Williston Basin

Polar & Divide

33

Williston Basin – Asset Overviews

Bison Midstream, associated natural gas gathering system located in Mountrail and Burke counties in North Dakota

– Approximately 303 miles of polyethylene pipeline and 89 miles of high-pressure steel pipeline

– Average throughput of 18 MMcf/d in 1Q 2015 from eight customers

– 26 MMcf/d of throughput capacity at six compressor stations

– Low-pressure gathering services provided primarily under fee-based contracts with major Williston producers

– MVCs average 10 MMcf/d through 2019

Polar & Divide, crude oil and produced water system located in Williams and Divide counties in North Dakota

– Approximately 298 miles of pipeline

– Average throughput of 48 Mbbl/d in 1Q 2015

– 80 Mbbl/d of throughput capacity

– Gathering services provided under fee-based contracts with major Williston producers

Asset Details Map of Williston Assets(1)

Crude oil, produced water and associated natural gas gathering from over 850,000 net acres dedicated through 2027

Stampede Lateral

Bison

Polar & Divide

Constructed

Under Construction

Polar & Divide

(1) Little Muddy and Stampede Lateral expected to be in service by the end of 2015.

34

DFW Midstream – Strategic Position in Core of Barnett Shale

Barnett Shale EUR IsopachBarnett Shale Overview

DFW system primarily located in southeastern Tarrant County, Texas

DFW’s service area encompasses the “core of the core” of the Barnett Shale

– Average per well EURs in excess of 4.1 Bcf(1)

– 5 of the 10 largest Barnett wells ever drilled, including the two largest, are flowing on the DFW system

DFW System

DFW’s service area includes the most prolific part of the Barnett Shale with the largest wells

Source: Netherland, Sewell & Associates, Inc.(1) Netherland, Sewell & Associates, Inc. estimate as of 3Q 2012.

35

128-mile natural gas gathering system primarily located in southeastern Tarrant County, TX

Low-pressure wellhead gathering under long-term, fee-based contracts which include:

– 186 Bcf of MVCs through 2020

– 108,314 acres dedicated through 2030

Average throughput of 403 MMcf/d in 1Q 2015 from nine customers

Six primary interconnects serving Waha, Carthage, Katy, Perryville and Henry Hub

DFW Midstream – Asset Overview

Asset Details

Gathering from 76 pad sites in the “core of the core” of the Barnett

Map of DFW Midstream

36

DFW Midstream – Leveraged to Existing Infrastructure Given urban environment, DFW’s customers are drilling multiple

wells from single pad sites

– Producers trying to minimize surface footprint

DFW has connected 76 drill pad sites

Producers have drilled and completed an average of 5 wells per pad

– Pad sites can accommodate up to 30 wells

High density pad site drilling leverages scale of DFW Midstream

– Once pad site is connected, additional wells are added at little to no capex

Core of the core is the last part of Barnett to be developed -significant future development remains

– DFW’s AMI is approximately 25% developedHigh Density DFW Pad Site – 22 Wells

Average DFW Pad Site – 5 Wells

2 wells 3 wells

37

Grand River – Asset Overview

1,779 mile natural gas gathering and processing system servicing more than 45 producer customers in western Colorado and eastern Utah

– Includes legacy Grand River system and Red Rock system acquired by SMLP (and merged into Grand River) in March 2014

Average throughput of 615 MMcf/d in 1Q 2015

Natural gas interconnects with downstream pipelines service Enterprise Products Partners L.P.’s (“Enterprise”) Meeker Plant, Williams Partners L.P.’s Northwest Pipeline system, and Kinder Morgan Inc.’s TransColorado Pipeline system

Processed natural gas liquids are injected into Enterprise’s Mid-America Pipeline system

Fee-based revenue from long-term contracts include:

– 2.1 Tcf of MVCs through 2026

– 670,960 acres dedicated through 2036

– Annual fee escalators subject to CPI or PPI

Asset Details

Positioned in the core of the Piceance Basin with exposure to the liquids-richMesaverde formation as well as the emerging Mancos & Niobrara formations

Map of Grand River

38

Legacy Grand River – Actual & Contracted Throughput By System

Mamm Creek Gathering System

376 356 347 342 319 309

0

100

200

300

400

500

4Q'13 1Q'14 2Q'14 3Q'14 4Q'14 1Q'15

MMcf/d

Actual Throughput Contracted Throughput

MVCs in place with Encana, WPX, Vanguard and Ursa Resources

Certain customers currently flowing in excess of MVCs while others are below and making shortfall payments

Given the high level of MVCs, throughput volatility does not necessarily impact cash flow

Orchard Gathering System

38 36 35 33 31 30

0

50

100

150

200

4Q'13 1Q'14 2Q'14 3Q'14 4Q'14 1Q'15

MMcf/d

Actual Throughput Contracted Throughput

South Parachute Gathering System

69

96 83 77 74 70

0

20

40

60

80

100

4Q'13 1Q'14 2Q'14 3Q'14 4Q'14 1Q'15

MMcf/d

Actual Throughput

Declining throughput at Orchard given Encana delays related to Mancos / Niobrara drilling activity

MVCs are in excess of throughput, thus, throughput volatility does not impact cash flow

MVCs grow at 20.6% CAGR from 2013 – 2015

No MVCs

Legacy Grand River MVCs increase at a 5.7% CAGR from 2013 – 2015and include annual fee escalators tied to CPI or PPI