|Open-File Report 2005–1229
Rock-Fall Hazard Assessment of Little Mill Campground, American Fork Canyon,
Uinta National Forest, Utah
By Jeffrey A. Coe, Edwin L. Harp, Arthur C. Tarr, and John A. Michael
Prepared in cooperation with the Pleasant Grove District, Uinta National Forest
In July 2004, at the request of Pam Gardner, District Ranger for the Pleasant
Grove District of the Uinta National Forest, Ed Harp of the U.S. Geological
Survey (USGS) conducted a preliminary assessment of the rock-fall hazard
at Little Mill campground in American Fork Canyon, Utah. The campground
has had a history of rock-fall activity and lies immediately east of
a former U.S. Forest Service (USFS) picnic site (Hanging Rock picnic
area) where two people were killed by separate rock-fall incidents in
the mid-1990s. Harp’s preliminary assessment of rock-fall hazard at the
campground indicated that parts of the campground were located immediately
downslope from active talus chutes and that rock from some previous falls
had traveled through the campground and across the adjacent American
Fork River. Harp concluded his preliminary assessment with the recommendation
that a detailed assessment of rock-fall hazard at the campground be conducted using a combination of field- and aerial-based methods.
The USFS funded the USGS to conduct this detailed hazard assessment in
October and November, 2004. This report describes the methodology, results,
and conclusions from the detailed hazard assessment.
|Posted July 2005
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