Baldy Mountain is a 9,892-foot summit in the Centennial Mountains on the Idaho–Montana border and the Continental Divide, just south of Red Rock Lakes National Wildlife Refuge. It is the third-highest peak in the range and the highest point in the Centennial Mountains Wilderness Study Area. Rising about 3,300 feet above Lower Red Rock Lake across 3.8 miles, it has moderate relief rather than a sharply abrupt profile. Its position on the divide sends runoff north toward Lower Red Rock Lake and the Red Rock River, and south into Ching Creek in Idaho. In a subarctic climate, it is a prominent high point in this remote border landscape.