The standard, least technical route on the only 14er inside Rocky Mountain National Park, and one of the most serious standard routes on any Colorado fourteener.
The Longs Peak Trailhead (Longs Peak Ranger Station) sits about 10 miles south of Estes Park, reached via Colorado 7. Parking fills very early on summer mornings; most parties start in the dark, often before 3 a.m. From the trailhead at about 9,405 feet, a well-graded trail climbs steadily through Goblins Forest and past Mills Moraine to the Boulder Field, a broad talus basin below the peak's northwest side, reaching the Keyhole — a distinctive notch in the ridge — at about 13,150 feet. Beyond the Keyhole, the route crosses the Ledges (an exposed traverse), climbs the Trough (a steep, loose gully), crosses the Narrows (a airy ledge traverse), and finishes up the Homestretch, a steep slab section, to the summit. All four sections involve real exposure and hands-on Class 3 scrambling.
Reverse the route exactly — the Homestretch, Narrows, Trough, and Ledges are all more consequential to down-climb than to ascend, and route-finding errors on the descent are a leading cause of incidents on this mountain.