Challis Field Office
721 East Main Ave Suite 8
Approximately 1 mile northwest of Mackay, Idaho along the Big Lost River. Turn west off of Hwy. 93 onto Main St. in Mackay. Continue south; Main Street turns into Smelter Road and crosses the Big Lost River (there is a signed IDF&G public river access on the southeast side of the bridge). Proceed approximately 1 mile, cross the cattleguard and turn right. Follow this road approximately 2 miles to the signed day use parking area for the Big Lost River Access Trail, located on the north side of the road.