Top 5 day hikes in Colorado, and how early you have to be off each one

A shelf of travertine hanging off the wall of Glenwood Canyon, holding a lake the color of a swimming pool with waterfalls tipping into it. It is a National Natural Landmark, and the walk up to it gains 1,200 feet in a bit over a mile — steep and rocky in a way the mileage does not warn you about.

Getting in is a timed-entry permit: $12 a person, required all year, booked in hourly slots that give you a three-hour window on the trail. The Forest Service, the City of Glenwood Springs and a concessionaire run it between them, and you drive yourself to the Hanging Lake Rest Area off I-70. Ride-shares are not allowed to drop you there.

This is the one on the list with news attached. The 2020 Grizzly Creek Fire and the flooding that followed it shut Hanging Lake down for years, and the rebuilt trail only reopened in June 2026. A burn scar sitting above a canyon means the trail can still close at short notice after heavy rain, and permits are refunded when it does. Check the day before rather than the week before.

No dogs, no fishing, and no getting into the water at all — not swimming, not wading, not a hand in it. The travertine that makes the lake is what the rules are protecting.

There is no trail, which is the whole character of the thing. You cross half a mile of the Medano Creek bed and then zigzag up the ridgelines, and every step gives back a portion of itself. The Park Service puts the round trip at two and a half miles and two hours on average — and says to allow up to four if you are not used to the altitude. Four hours, for two and a half miles.

It is honest about the name, too. High Dune on First Ridge is "neither the highest in elevation nor the tallest in the dunefield, but it looks that way from the main parking lot." The genuinely tall ones sit further in: Star Dune at 736 feet, a six-mile round trip, and Hidden Dune at 741, the tallest in North America, at seven miles. Those are a different day out.

Then the sand. The surface can reach 150°F on a summer afternoon, which is why the Park Service tells you to hike in the early morning or the evening, and why it wants boots and long trousers rather than sandals. The park sits between 7,520 and 13,604 feet, with the visitor center at 8,170, so you are dealing with altitude and heat at the same time.

And lightning. An open dunefield leaves you as the tallest thing for a long way, and the park's advice is to come down off the dunes because lightning will often strike the dunefield. It leaves fulgurites behind — sand fused into glass — which is a fairly direct way of telling you how often that happens.

Colorado's most-climbed fourteener, and the reason is that the standard east ridge route is a walk rather than a scramble. The USGS puts the summit at 14,265 feet. Breckenridge Tourism Office gives the round trip as 6.6 miles and rates it difficult; Summit County says the average hiker takes about six hours. Being a walk-up is exactly why people underestimate it — the difficulty is the altitude and the exposure, not the moves.

Most of the route is above the trees, which makes the timing arithmetic simple and unforgiving. Six hours from a 5 a.m. start puts you back at the car around eleven. Six hours from a nine o'clock start puts you on an open 14,000-foot ridge at noon. The county's own advice is that hikers are strongly encouraged to start early in the morning to avoid dangerous afternoon thunderstorms, and it is the operator of the car park saying that, not a guidebook.

Summit County has run a parking and shuttle system here for six seasons. In 2026 it ran from 13 June to 13 September: either reserve a space at the trailhead or ride the shuttle up from the Breckenridge South Gondola parking structure. A full day at the trailhead, 5 a.m. to 3 p.m., is $30 Monday to Thursday and $55 Friday to Sunday and on holidays; a four-hour slot is $10 or $20 on the same split.

The shuttle runs 5 a.m. to 5 p.m. and costs $7 for visitors, free for residents. Reservations open two weeks ahead of your date.

After 3 p.m. the trailhead parking is free and first-come, and outside the season it is free and unreserved — neither of which helps you, because both mean starting late. There is no parking on the county roads at any time and it is enforced.