One of the best things about living in Colorado is that you can go big and go home. Because the peaks are so close, it’s easy to stretch the definition of “day hike” to mean all the terrain you can cover in 24 hours. We aren’t going to go quite that big, but the following ten hikes will make you late for supper (and possibly work the next day).

Longs Peak

15 miles round trip; 5,100 vertical
Rocky Mountain National Park

Keyhole Longs PEak

The famous Keyhole on Longs Peak, where the real work begins.

Longs Peak is one misunderstood mountain. The 14,259-foot landmark is one of the more difficult 14ers in Colorado, yet it lures many casual hikers to its slopes every season. The responsible way to day hike the standard Keyhole route on the peak is to begin around 2 a.m., in order to beat the afternoon storms that inevitably roll in around 2 p.m. (or earlier) during the summer. The first 5.5 miles are a gradual walk up a well worn trail, terminating at a large boulder. Once you’re there, the work is just beginning. Pop through the famous keyhole and you face another two miles of exposed class 3 scrambles, a devilishly steep gully and a bit more exposed (and often crowded) rock before topping out. Then you have to get down. Is it worth it? Indeed! But we strongly suggest you warm up on a few less strenuous peaks prior to hitting up Longs.

Peak 1 to Peak 6 Traverse

12+-mile loop; 8,000+ vertical
Ten Mile Range

james dziezynski colorado

The author enjoying the Tenmile Range traverse.

The great thing about Peak 1 is that it starts from an easy-to-access trailhead off I-70, where it’s legal to park overnight (as long as you don’t pitch a tent). You start out with a stiff, steep class 2 hike 2.8 miles to the summit of this 12,805-foot beauty. The views from the top are some of the best in Colorado. From the top of Peak 1, you could turn around and go home—or keep rolling along the numbers peaks. Beyond Peak 2 (a.k.a. Tenmile Peak), the terrain is fun class 2 and 3, with some great scrambles on relatively solid rock. After Peak 4, the terrain eases back to rolling class 2 tundra. A well-worn trail between Peaks 5 and 6 merges with the Colorado Trail and makes it possible to do a long loop of about 12 miles. Of course, if you’re feeling burly, keep on going all the way to Peak 10 at the Breckenridge ski area (making for a 20-some-mile loop). There’s a bus that runs between Breck and Frisco if you want to avoid bringing two cars.

Pawnee Pass/Lone Eagle Peak

18.5 miles round trip; 6,500 vertical
Indian Peaks

PAwnee Pass

Views from Pawnee Pass looking west.

From the Long Lake Trailhead, a day-hike to Pawnee Pass and back is itself a worthy outing—a little over eight miles round trip. But since we’re going big, why not continue the fun and go over Pawnee Pass? The western Indian Peaks are lightly traveled and offer amazing views of the hidden mountains and lakes tucked in the heart of the range. If you really want to up the ante, push to the top of the imposing Lone Eagle Peak, an 11,920-foot spire with a spooky, exposed class 4 scramble to the top (you will want to bring a rope). If you are confident in your alpine rock skills, there’s a classic 11-pitch, 5.7 climb up Lone Eagle’s North Face. Most climbers camp at Crater Lake or Pawnee Lake.

St. Vrain Glaciers

16+ miles round trip; 2,600+ vertical
Peaceful Valley / Camp Dick

Ogallala PEak

Looking out towards Ogallala Peak.

This tour gains elevation slowly and stays over 8,600 feet the entire way—a good workout that won’t scare you. Starting from the Peaceful Valley campground, the St. Vrain Glacier trail follows the Middle St. Vrain Creek over 8 miles into the heart of the basin (the trail tends to fade out around mile 6), where 13,138-foot Ogalalla Peak reigns over it all. There are six established year-round glaciers hidden back here and the camping is sublime. The cirque of peaks can be navigated from below or above, though adding summits to this route could potentially push even strong hikers to a 15+ hour day and over 20 miles. Ouch!

Isolation Peak / Moomaw Glacier

17 miles round trip; 5,000 vertical
Rocky Mountain National Park

Moomaw Glacier

The Moomaw Glacier from Tanima Peak.

At 13,118 feet, Isolation Peak is deep in the heart of Rocky Mountain National Park’s Wild Basin and you’ll have to cover rugged terrain to bag it. But the tour through Wild Basin is gorgeous—this is arguably the most beautiful wilderness on the Front Range. About 1.5 miles away from Isolation Peak is the tiny, hidden Moomaw Glacier, a nice alternative destination if you want a big day without the big peak. Few go here, but it’s just one of many hidden treasures in the least traveled part of the park.

UN 13,001 and Lost Man Lake

6.2 miles round trip 1,700 vertical
Independence Pass

Lost Man Lake.

Lost Man Lake.

A low-key trailhead a mile west of the summit of Independence Pass accesses one of Colorado’s best overlooked mountainous playgrounds. Begin by navigating a maze of colorful willows that open up to grassy alpine meadows highlighted by Independence Lake. From here, several good mountain scrambles may tempt you off the trail, including 13,380-foot Geissler Mountain and 13,711-footTwining Peak. If you choose to go over Lost Man Pass (2.5 miles one way), you enter pure Colorado wilderness—Lost Man Lake and UN 13,001, Colorado’s lowest officially ranked 13er (a fun class 2 or easy 3 scramble). If you plan to stay a while, the backpacking potential here is excellent.

Eccles Pass to Red Buffalo Pass

12 miles round trip; 3,124 vertical
Frisco

Red PEak Colorado

Looking north to Red Buffalo Pass and Red Peak.

The standard trailhead for Eccles Pass is Meadow Creek, a mere stone’s from I-70 and Frisco. One of the state’s most spectacular trails in autumn, this aspen-lined corridor opens up to a grassy meadow that contains several small alpine lakes. Eccles Pass is roughly 4.5 miles from the start of the trailhead but don’t stop there! You can visit Eccles Peak to the east or Deming Mountain to the west… or head north into the gorgeous South Willow Creek Basin (premiere backcountry camping territory, we might add). Just under 6 miles in is Red Buffalo Pass, a good turnaround point for a long day hike. From Red Buffalo Pass, you can also earn bonus points by scrambling the class 3+ ridge back to Eccles Pass.

Guardians of the Flatirons Traverse

13 miles; 6,800+ vertical
Boulder

South Boulder Peak

South Boulder Peak and the new burn area.

Who says you need to leave civilization to have a huge mountain day? This epic 13-mile loop gains over 6,800 feet of elevation total and hits the three impressive peaks that stand above the Flatirons: Green Mountain (8,144 feet), Bear Peak (8,461 feet) and South Boulder Peak (8,549 feet) Starting from Gregory Canyon, the route tops Green Mountain first, then follows the Green-Bear trail to Bear Peak. From Bear, connect to South Boulder Peak, then descend Shadow Canyon (the option to leave a car at the South Mesa trailhead in Eldorado Springs can make this a shorter point-to-point). From Shadow Canyon, follow the Mesa Trail 6.7 miles back to Chautauqua Park and, eventually, where you started.

Betty and  Bob Lakes

12 miles round Trip; 2,700 vertical
Eldora

Indian Peaks' finest alpine lakes! (courtesy of meetup.com)

Indian Peaks’ finest alpine lakes! (courtesy of meetup.com)

The Hessie Trailhead begins where the main road through the tiny town of Eldora ends. This is a popular trailhead year round, though most people are just here to make the short one-mile hike to Lost Lake. If you keep going, you will be treated to a wonderful, wooded trail that eventually breaks treeline roughly 5 miles in. This basin shelters three named alpine lakes: King Lake, Betty Lake and Bob Lake (11,570-foot Bob being the farthest in at 6 miles). There’s also a trio of unnamed smaller ponds. It’s a quiet wilderness destination that’s also a nice place to camp (permit rewuired in summer). Return the way you came for a fine 12-mile outing (and a nice warm-up for Longs Peak, if its on your hit list).

Grizzly Peak–Torreys Peak– Grays Peak

8.1 miles one way; 4,800+ vertical
Loveland Pass

Mount Edwards

Mount Edwards from Torreys Peak.

This route is a true point-to-point, so you will need two vehicles. The hike may sound short at 8.1 miles, but the adventure value is high! Get ready to gain close to 5,000 verts—all while never dropping below 11,300 feet. Begin at the top of Loveland Pass and grind up a steep slope to a long ridge that eventually connects with 13,427-foot Grizzly Peak. From here, connect via a class 2 or easy 3 ridge southeast to 14,267-foot Torreys Peak. A well-worn and heavily traveled path connects Torreys to 14,270-foot Grays Peak, where a busy trail leads down to the ending parking lot at Stevens Gulch trailhead. Want a bonus? Traverse 1.28 miles over to lonely 13,950-foot Mount Edwards (if you want to make this a point-to-point, leave a 4×4 vehicle at either Waldorf Mine on the east or Horseshoe Basin to the west).

jd-thumbElevation Outdoors contributing editor James Dziezynski is the author of Best Summit Hikes in Colorado. Visit his Mountain Air Blog or follow him on Facebook and Twitter.