July: Trail Ridge Road crosses the tundra at 12,000 ft with alpine wildflowers at their peak. Longs Peak and the high lakes are typically snow-free enough to reach.
September: Elk rut season. Bull elk bugle in Moraine Park and Horseshoe Park at dawn and dusk, and aspen groves peak gold in the second half of the month. This is RMNP's most spectacular month.
Permits and reservations
Timed-entry reservations are required in summer and fall: May 22 – Oct 12, 2026, 9 a.m.–2 p.m. for most of the park and 5 a.m.–6 p.m. for Bear Lake Road.
Timed entry / Timed entry + Bear Lake Road: Released on the 1st of each month at 8 a.m. MT for the following month (May 1 for late May–June, June 1 for July, and so on). Additional reservations release at 7 p.m. MT the night before. $2 Recreation.gov fee.
Campgrounds: In summer, Moraine Park, Glacier Basin, Aspenglen and Timber Creek campgrounds must be reserved ahead on Recreation.gov. Reservations cannot be made at the campground or visitor centers.
Backcountry camping permit: Overnight camping outside the campgrounds needs a backcountry permit. See the park's permits page for how to get one.