The Lost Gold Trails Loop ventures off the Fort Henry Historic Byway at the "Y" Junction onto County Road A-2. The loop then travels southwest along the desert-lava rolling hill terrain where cattle and wild game peacefully share the spring and fall months grazing.

Crossing the railroad, which originated the town of "Dry Creek," now Dubois, and traveling west through town over I-15 overpass on Idaho 22, you connect with Old Highway 91.

Turn north on Old Highway 91 and head to Spencer, passing near the US Sheep Experiment Station. This early-day Gold Trail closely follows Beaver Creek towards the Montana gold mines.

At Spencer the Gold Trail of yesterday becomes the Opal Trails of today and passes several high grade Opal Shops within the original Wood Live Stock town site.

Leaving Spencer, the trail heads east to Idmon. This early day Nez Perce Trail has spurs off its main roadway to private opal mines, Caribou-Targhee Forest fishing and primitive camping areas, and an old cemetery, connecting again to the Fort Henry Historic Byway at the old Idmon town site.