Line © OpenStreetMap contributors (ODbL), checked by Global Adventurer.
The hike
The walk starts at the Chautauqua Trailhead by the Ranger Cottage in Chautauqua Park, on Baseline Road in Boulder. Paths lead up through the park to the Bluebell Shelter, where the Royal Arch Trail begins. It climbs steeply through pine woods to Sentinel Pass, drops a little, then climbs again to Royal Arch, a natural rock arch in the Flatirons with views out over Boulder and the plains. Return the same way.
It is 3.4 miles (5.5 km) round trip with 1,180 feet (361 m) of climbing; allow about 2½ hours. The grade is Moderate: it is short, but the climb is steep and rocky, with tight switchbacks and some big steps.
The city describes the trail as medium to hard: loose rock and large steps make it harder than its length suggests, and the trail can be confusing, so carry a map and extra water. It is a busy trail, and dogs are allowed.
On summer weekends and holidays (May 23 to September 7 in 2026), parking at Chautauqua costs $2.50 an hour and a free Park-to-Park shuttle runs from downtown Boulder; at other times parking is free. Until November 30, 2026, stormwater work may disrupt the Chautauqua parking lots.
Route drawn by Global Adventurer along OpenStreetMap paths (© OpenStreetMap contributors, ODbL), with figures worked out from it. Check the forecast and the ground on the day: paths change.
Good to know
- A natural rock arch in the Flatirons, framing a view out over Boulder and the plains
- A stiff climb to Sentinel Pass, then a short drop and a final steep pull to the arch
- Starts at Chautauqua Park, whose car park fills early on summer weekends
Getting there
Start: Chautauqua Trailhead. 39.99925, -105.28273
Places to stay nearby
Rooms in and around Colorado Rockies: Booking.com → Expedia →
Affiliate links: if you book, Global Adventurer earns a small commission at no cost to you.
Paths change, and the weather decides the day. The line and figures come from OpenStreetMap and our own checks; take a map, check the forecast, and turn back if it isn't right.
