Why we love it: Because it’s truly a challenge—and victory is especially sweet after three previous attempts. Plus, the sunrise is spectacular.

When to go: August is the best, and July and September are feasible if the weather gods are smiling, but you’re more likely to encounter snow and hazardous conditions.

Quick tips: The campground at the base of Longs often fills to capacity early on weekends. If you plan to drive up to camp after work on Friday or later in the day on Saturday, consider turning onto one of the forest access roads off CO-7; we like County Road 82: The dirt road winds through private property until it hits secluded national forest land a few minutes in. Pitch your tent in the unofficial camp spots off the road or set up wherever you see fit for an early morning departure. No fuss, and you’re still just a few minutes’ drive from the trailhead at 2:30 a.m.

Also: Because of its entrenched “Colorado-ness,” easy access, and legendary reputation, Longs lures some people into making it the first fourteener they attempt. If you’re one of those people considering it: Don’t do it. This is not the mountain to experiment with. You’ll thank us later.

***

Longs Peak had been taunting us forever. Three times over the past few years, my fiancé and I had hit the trailhead at the ranger station in the chilly darkness of the morning’s wee(est) hours, headlamps bobbing, backpacks crammed with trail snacks, and water heavy in bottles. Three times we’d turned back before the summit, defeated by quick-moving storms that spat hail, rain, snow, lightning, and cruel, unforgiving gusts of wind upon us. On our first hike, a ranger intercepted us and sent us down due to a pending rescue being conducted on the trail above.

So, two weekends ago, as we finally stood atop Rocky Mountain National Park’s highest peak (elevation: 14,259 feet) on attempt number four, we were especially triumphant. The sun was shining. The 360-degree views were astounding. The mood amongst our fellow summitters was jovial. Our picnic sandwiches and fruit could have been a feast fit for kings. And the air was thin…really, really thin. My feet ached. My arms ached. My shins ached. My quads ached. We had worked our behinds off to make it up the last mile of the Keyhole Route—the last mile that begins as soon as you pass through the rocky keyhole formation (pictured) at the top of a giant incline of what looks like a massive rockslide, appropriately named the Boulder Field.

This 15-mile roundtrip route is by far the most popular, as it doesn’t require technical skills during the summer months. (For a list of less traveled and more dangerous routes, click here.) Supposedly, 9,000 trekkers attempt it every year, and about half reach the summit. We’d never made it past the keyhole before, and our knowledge of what was beyond was based solely on our reading and the accounts of others. But we’d practically memorized the trek up: a forested beginning that winds to the Chasm Lake overlook and a spectacular place to watch the brilliant sunrise, then a series of switchbacks that dump you into the Boulder Field and a handful of campsites where those who prefer to split the hike into two days can set up shop for a night. After a 4 a.m. start, we arrived at the Keyhole by 9 a.m. No sweat, we thought…we’d be off this mountain by 3 p.m.

That last mile was the longest mile of my life. It’s broken down into sections: The Ledges, the Trough, the Narrows, and the Homestretch. The people who came up with the name the “Narrows”? Not. Joking. Around. During several harrowing stretches, only one person can pass at a time, and one misstep could send you careening down the backside of the mountain. Do not even think about this hike—better phrase: scramble—if you don’t have excellent, grippy treads on your boots. And if you’re even remotely afraid of heights? Not a prayer. This is a hand-over-hand maneuvering exercise along a completely exposed rock face. It is tricky.

All in all, our total on-mountain time, including plenty of extended, leisurely breaks and even a catnap on the summit thanks to the unusual good favor of the weather gods that day, was 15 hours. They say that’s within a normal range. We felt like it was an eternity. But it’s an eternity we can check off the Colorado bucket list.

Getting there: Take U.S. 36 West for about 37 miles through Boulder and into Lyons. In Lyons, turn left onto 5th Avenue and after .5 miles, continue onto South Saint Vrain Drive/CO-7 west toward Allenspark. Drive 24 miles until the left-hand turn onto Longs Peak Road. Continue about a mile to the trailhead and ranger station.