The strenuous North Boundary Trail starts from the Cow Creek Trail
in the northeast corner of Rocky Mountain National Park and reaches the North Fork Trail
intersection along the North Fork Big Thompson River. This is an isolated journey with significant changes in elevation, so be prepared.
From the Cow Creek trailhead, head west briefly on the Cow Creek Trail
through McGraw Ranch to the North Boundary Trail split. Turn right (north) and run the North Boundary Trail as it rises steadily through a ponderosa forest, joining aspen and spruce as you ascend. Well-spaced trees provide good sight lines for wildlife in this area. Travel steepens considerably through a narrow gulch topped by large granite domes to a dividing ridge between the Cow Creek and West Creek drainages.
Enjoy north-south views before descending steep, tight switchbacks that ease near the valley floor. Next, the trail crosses West Creek and follows it to the intersection with West Creek Falls Trail
. If time permits, this is a worthwhile detour. Here, the North Boundary Trail bends north and climbs up from the creek, leveling through an open rocky area with good views of the Mummy Range. The trail contours around a second major hilltop and quickly descends across a small stream and Fox Creek. Then turn uphill and begin the third and most taxing climb, surmounting nearly 1,300 feet in just 1.5 miles. Reach a narrow crest - the trail's highest point - and cover level ground that affords commanding views of the valley below.
The North Boundary Trail drops gradually through mixed pine and crosses an unnamed creek to the Silvanmere Backcountry Campsite, past which the trail ambles over mellow terrain to the North Fork of Big Thompson River and its terminus at the North Fork Trail
parts of the North Boundary Trail pass through the Comanche Peak Wilderness Area where hunting is allowed. Stay on designated trails and wear bright clothing during the hunting season.
Ponderosa, aspen, spruce, lodgepole, fir.