Rock-Fall Hazard Assessment of Little Mill Campground, American Fork Canyon, Uinta National Forest, Utah

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.

[Summary provided by the USGS.]