Timbered Dome is the southeasternmost named Pioneer Mountain summit. It is located WNW of Arco, Idaho. It is in fact, dome-shaped and timbered. It can be approached via rough 4WD roads from both the east and the west. A good map will help you get there. See John Platt’s trip report. USGS Champagne Creek
Timbered Dome. John Platt Photo
Timbered Dome from Big Cinder Butte in Craters of the Moon National Monument. The Lost River Range is in the background. Sheep Mountain (White Knob Mountains) is to its left.
The USGS triangulation remnants atop Timbered Dome, looking north to the Lost River Range (5/22/94). Rick Baugher Photo