From Boise:

Take ID-55 to Banks. Turn right on Banks-Lowman Highway (ID-17) going East to Lowman and the junction with ID-21. Turn left on ID-21 and follow it 57 miles to Stanley.

Alternate Route: Take ID-21 all the way from Boise, passing Lucky Peak Reservoir and directly through historic Idaho City and Lowman. It’s approximately 130 miles one way.

From Twin Falls:

Take US-93 North from Twin Falls, which changes to ID-75 at Shoshone. Follow ID-75 through Ketchum and 60 miles further north to Stanley.

From Sun Valley:

Take ID-75 north for 60 miles to Stanley.