Tom Thumb is an easily sighted geomorphic structure near the northwest end of the Sauceda mountains and as such is a distinctive destination for desert travelers curious about its origin. The Sauceda Mountains are on the Barry M Goldwater range and permits are required to enter the area. The Thumb is climbed perhaps one or more times per year while the nearby hills which are more accessible see more visitors. It's prominence has made it a regular notation on maps of the area. Tom Thumb is also remote and a 4Wheel drive vehicle and some discretion are needed to reach it. One approach is up Ryan's Wash from RT 85, a total distance of about 30 miles from Ajo.