East Portal Loop

East Portal Loop is a 5.8-mile circuit from the road end near the gate, climbing from the Alva B. Adams Tunnel outlet and following the Wind River through forest and marshy meadows before returning below Emerald Mountain. Allow about 3 to 4 hours for roughly 950 feet of climbing and descent. It suits you if you want a quieter forest walk with a distinctive human-made landmark at the start and are comfortable following several junctions.

Walk past the gate to the outlet pond, then take the steep road climb. Water from Grand Lake travels under the Continental Divide through the roughly 13-mile Alva B. Adams Tunnel before entering the Wind River here. The tunnel was completed in 1947. Beyond the climb, the route leaves the road and follows the smaller river under trees.

The forest opens into marshy meadows and small ponds. At the junction, turn right over a slight ridge, then right again onto the horse-used trail. Near Glacier Basin Campground, turn right to skirt below Emerald Mountain and descend across an open hillside toward the pond. The route uses several different trail segments, so keep a map handy and watch each turn; yield to horses on shared trails.

From Highway 36, take Colorado 66 toward the YMCA and continue to the end of Tunnel Road; the described start is the parking area by the gate. The exact public-access arrangement at the road end and the lot's size or fees could not be confirmed, so verify access before setting out. No trail-specific toilet or drinking-water information was found. Pets are prohibited on Rocky Mountain National Park trails.