Royal Arch Trail

Royal Arch is the natural sandstone arch below the Flatirons, 1.7 miles above Chautauqua Park, and the hike to it is Boulder's most popular: a steep climb on rock steps through the pines with a false top at Sentinel Pass, a short drop, and a final scramble to the arch, where the view runs east over the city and the plains. It is 3.4 miles round trip with 1,400 feet of gain.

From the Chautauqua trailhead, follow the Bluebell Road up through the meadow to the Bluebell Shelter, then take the Bluebell-Baird trail and the signed Royal Arch trail into the trees below the Third Flatiron. The trail climbs steadily on stone steps built into the slope, crossing Bluebell Canyon and passing under the rock.

Above the canyon the trail steepens to Sentinel Pass, a saddle at about 6,950 feet that looks like the top and is not. The trail drops about 100 feet from the pass and climbs the last stretch on rock steps and a few short scrambles to the arch. Walk under it for the view. Return the same way; the steps are hard on knees.

Chautauqua Park is at the top of Baseline Road in Boulder. The lot and the surrounding streets charge for parking on weekends and holidays from late spring through early fall, and the lot is full by 7 AM year-round on weekends; Boulder runs a free park-to-park shuttle from downtown and the CU campus on those days. Weekdays are easier. No permit. Toilets and water at the Ranger Cottage.

Dogs are allowed and must be leashed the whole way; the Royal Arch trail is not a voice-and-sight trail. The rock steps and the scrambles near the arch are why the trail is listed for older kids; school-age children who climb do fine. Carry water; there is none above the Ranger Cottage. The arch itself is fragile and climbing on it is prohibited. Boulder is at the trailhead. The Boulder hikes page lists the Flatirons trails, and Green Mountain starts from the next trailhead up Flagstaff Road.