Earthquake Activity

Kirkham Hot Spring

Directions: On Highway 21 to Lowman, ID, turn left on the Banks-Lowman Road or take Highway 55 north to Banks, turn right on Banks-Lowman Road.

Description: The Kirkham Hot Springs is easily accessible on foot from the Boise National Forest Kirkham Campground. Summer season is usually quite busy and nightly closure from 10:00 p.m. to 6:00 a.m. is strictly enforced. Steamy waterfalls and hot pools make this site very inviting to the weary traveler.

The Kirkham Hot Springs is part of the South Fork Payette Geothermal System (SFPGS). This series of thermal springs is located along faults that fracture the Atlanta lobe of the Idaho batholith. Seismic activity helps to keep the hydrothermal systems in this region active. An earthquake with the magnitude of 7.3, the highest magnitude ever recorded in Idaho, occurred as recently as 1983. Noticeable changes in flow rates of the springs were recorded near the epicenter, which was located just north of the SFPGS.

The Idaho batholith is comprised of Cretaceous period micaceous granites, leucogranites, and gradiorites. Tertiary plutons of granite and diorite are also present (Druschel et al., 2001).

Scenic Exposed Paunsaugunt Fault

Directions: Call the Beaverhead Ranger District for assistance at 435-438-2436.

Description: The Paunsaugunt Fault forms the southeast edge of the Paunsaugunt Plateau. Bryce Canyon's rim is also the dropped side of this fault. Along this fault, Cretaceous rocks border the Claron Formation. The capping Claron Formation, regionally ranging in age from Paleocene to middle Oligocene, can be identified by its pink, cliff forming features. Thought to have formed during the transition period from fluvial environments to deltaic and lacustrine conditions, the oxidized iron in the muds and silts contributed to the pink color indicative of the Pink Member. The White Member, a limestone with interbedded siltstone and few fossils, has eroded away and can only be seen on the highest points of the Paunsaugunt Plateau (Davis et. al 2003.)

Joe's Valley Overlook

Directions: From Castle Dale, UT, take Highway 29 west to Forest Service road 040. Follow this road north for about 8 miles to Forest Service road 034. Follow 034 about 10 miles south along the ridge of Trail Mountain to the overlook.

Description: At the overlook, you will be looking at a 75-mile long "graben" containing Joe's Valley Reservoir. A graben structure is formed when a block of the earth's crust between two parallel faults drops relative to adjacent blocks. The down dropped block or valley is the graben. This valley floor has dropped some 3000 feet below the surrounding plateau. It is the most prominent of several grabens on the Wasatch Plateau. Restroom facilities and interpretive signs are available.

Neffs Canyon Terminal Moraine

Directions: From I-215 out of Salt Lake City, UT, take the 3800 S. exit. Turn right on Parkview Drive (4245 S.) and then left on Park Terrace Drive (4260 E.). Turn right on White Way (4275 S.) and follow road to White's Park where the Neff's Canyon Trailhead is located.

Description: The north slope of Mount Olympus ascends above you from the trailhead and large triangular ridge exposures of Tintic Quartzite are apparent from the trail. In the beginning, the trail follows an old road with remnants of pipelines that once carried irrigation waters to the farmlands below. The road soon gives way to a small stream and then a footpath that continues up alluvium deposits. On the south slope, Tintic Quartzite is still visible. The Humbug Formation with its thrust faults and deformation is seen on the north slope. As the trail continues upward, it crosses a small normal fault and then passes the Gardison Limestone, Deseret Limestone, and Fitchville formations. Just before reaching the meadow, the trail crosses a glacial moraine (Parry, 2005).