Participants will meet at the Sun Peak Picnic Site at 9am to carpool to the Lost River, the Salmon River and the Sawtooth Valley. The day will start by driving fifty miles over Trail Creek summit to the Mackay Dam, a rather shocking vestige of low-budget agricultural dams from the early 20th century. The Mackay Dam was not damaged during the November 1983 earthquake on the Borah Peak fault. Next, the outing will travel 90 miles north to Challis and west along the Salmon River to Yankee Fork, where the sabotaged 1920’s Sunbeam Dam formerly blocked the Salmon River for hydroelectric power to gold dredges. Crossing the Idaho batholith to Stanley, participants will return to Ketchum via Galena Summit, where there is a wonderful view of the Sawtooth Mountains.
Throughout the field trip, participants will learn about complex geology of central Idaho, mineral deposits, glacial features and the Cape Horn earthquake. Bring lunch, sturdy shoes, a jacket and sun hat.