"Native Americans, explorers, surveyors, and especially miners of the San Juan Mountains’ historic silver boom from 1882 to 1893 created numerous paths and passes into these rugged mountains. Situated above the spectacularly quaint town of Ouray (U-ray) at the base of Red Mountain Pass, the Portland Trail—leading to the Portland Silver Mine—is one such path. A half-mile south of Ouray and up US Hwy, you’ll find the turnoff to the Uncompahgre National Forest’s Amphitheater Campground and parking area, where the Portland Trail begins.
The Portland Trail enables hikers to adjust to the altitude of the San Juan Mountains on a path much less traveled than the Cascade Falls trails, although they intersect at numerous points. Surrounded by 12,000 to 14,000-foot peaks, this trailhead begins at 8,265 feet in elevation, (the parking area is at 8,130 feet) and eventually tops out at 9,231 feet. It was built by miners at the Portland Silver Mine, which, itself was blasted into the side of a nearly vertical granite wall on the southwest side of this natural amphitheater."