You need not worry about getting lonesome on the 15-mile (full-day) round-trip to Longs Peak (14,259ft) summit, as it's the centerpiece of many a hiker’s itinerary. During summer, you’re likely to find a line of more than 100 parked cars snaking down the road from the Longs Peak trailhead.
This is a serious climb, and you should be prepared before taking it on. After the initial 6 miles of moderate trail to the Boulder Field (12,760ft), the path steepens at the start of the Keyhole Route to the summit, which is marked with yellow-and-red bull’s-eyes painted on the rock (while there are dozens of ways up, this is the easiest). Even superhuman athletes who are used to the thin air will be slowed by the route’s ledge system, which resembles a narrow cliffside stairway without a handrail. After this, hikers scramble the final homestretch to the summit boulders. The view from the top – snow-kissed granite stretching out to the curved horizon – is incredible. The round-trip hike takes anywhere from 10 to 15 hours. The rule in Colorado is you need to hit the summit before noon to avoid lightning storms, so expect an early alpine start.
For a shorter hike, head south just above tree line to make it to Chasm Lake, a high-alpine wonder that sits below the jagged face of Long's Peak signature Diamond, where heavy-duty rock gods and goddesses test their metal.
Overnighting at Longs Peak Campground is a good idea. The Keyhole Route is generally free of snow mid-July to October – otherwise you will need technical climbing skills and equipment to reach the summit. When you dial the Beaver Meadows Visitor Center, the prerecorded message will have information about the conditions on this popular route.