Driving into and out of Ouray, the Amphitheater forms the town’s remarkable eastern wall. During a period of heavy volcanism, Ouray and the surrounding mountains were saturated with pounds of ash and lava, which pooled in the valleys, filling crevices, and leveled the area. Later, as the earth cooled, two glaciers set on a crash course towards each other collided beneath the Amphitheater, grinding and carving at the rubble of a mass landslide thought to have given the landform its distinct face. The Portland Trail circles the deep bowl-shaped cirque left behind.
The trail can be reached by a number of access points, but the easiest is probably from the small parking lot at the far southeast end of the Amphitheater Campground. From there, a short 0.2 miles stretch brings you to a crossroads between the Lower Cascade Falls Trail
and the Portland Trail. Starting the loop counterclockwise, turn right onto the Portland Trail, where the route follows a wide ridge above a drainage before dropping towards its normally dry basin. Just after crossing over to the other side of the drainage, turn left at the next fork, now half a mile from the trailhead. If the campground is closed or the parking lot is full, the trail to the right leads to another trailhead on the Portland Mine Road.
As the trail strains higher into the basin, easy switchbacks aim towards a ridge above Portland Creek. Keep an eye on the southern side of the trail for sporadic clearings in the thick curtain of pine and oak to open up with views of the Amphitheater and Hayden Mountain. When the trail reaches its high point of about 9,250 feet, 2.2 miles in, a four-way junction gives you a number of choices.
Turning left to continue onto the Portland Trail, the rest of the loop looses 250 feet to cross a seasonal drainage, then climbs again to meet with the Upper Cascade Falls Trail #213
. Turn left once again, where the trailhead waits just 0.9 miles downhill. Combined with Cascade Falls, the loop is about 3.6-miles round-trip.
You're likely to spot the usual deer, mountain goat, wild turkeys, and squirrels. While uncommon, black bears and mountain lions aren’t unheard of along any of the Ouray area trails.