History of landsliding near the 10/11/09 Nile landslide

Profile line for the following slides

Jack & Lorraine Powell 2009

10/11/09 Nile

Landslide

Sanford Pasture Landslide

Cleman Mountain

Present Profile from Cleman Mtn to Eagle Rock just prior to the 2009 Nile Landslide

Cleman Mtn

Naches River Valley

Eagle Rock

Profile from Cleman Mtn to Eagle Rock Two Million Years Ago

Cleman Mtn

Naches River Valley

Eagle Rock

N2

R2

N2

R2

N2

R2

Cleman Mtn

Naches River Valley

Eagle Rock

Two Million Years ago folding of the earth and undercutting by the ancestral Naches River

destabilized the south slope of Cleman Mtn.

N2

R2

N2

R2

N2

R2

Ellensburg Sed.

Cleman Mtn

Naches River Valley

Eagle Rock

Two Million Years ago the Sanford Pasture Landslide filled the Naches River Valley with

1000 feet of landslide debris

N2

R2

N2

R2

N2

R2

Cleman Mtn

Naches River Valley

Eagle Rock

N2

R2

N2

R2

N2

R2

Under cutting by the Naches River over time destabilized the eroded edge of the Sanford

Pasture Landslide

Cleman Mtn

Naches River Valley

Eagle Rock

Thousands of years ago a landslide blocked the Naches River valley with 100’s of feet of debris

N2

R2

N2

R2

N2

R2

Ellensburg Sed.

This landslide from thousands of years ago was largely erode away leaving a hill were homes

were built. The old landslide scarp erodes into an 800 ft high talus slope.

Cleman Mtn

Naches River Valley

Eagle RockTalus

Ellensburg Sed.

N2

Coleman Sand

R2

N2

Coleman Sand

R2

N2Coleman Sand

R2

October 11, 2009 the talus slope, which had been cracking since 2005, slides. Debris blocked the Naches River and moved the hill composed

of old landslide debris.Cleman Mtn

Naches River Valley

Eagle RockNile Slide

Ellensburg Sed.

N2

Coleman Sand

R2

N2

Coleman Sand

R2

N2Coleman Sand

R2

Nile landslide October 11, 2009