As you travel over the Blue Mountain Summit on U.S. 26, you'll see several places where the former road criss-crosses the current highway. Back in the 1930s this was U.S. 28. It was re-numbered in 1952.
Turn at FS Road 343 just east of the Forest Service boundary sign on the Blue Mtn Summit. Winter access could be challenging at best.
You're looking for a camoed plastic container.