Hiking Crosier Mountain Rainbow Trail in Northern Colorado

Important Update: The Cameron Peak Fire moved south into the Glen Haven area on Oct. 14, 2020, so this area likely looks much different now. For complete and up-to-date information on the Cameron Peak Fire, go to InciWeb and the Cameron Peak Fire Story Map, which includes tabs with maps of evacuation areas and area closures.

Mid-October 2020: The Cameron Peak fire has been ravaging the Cache la Poudre canyon since August 13. The smoke warnings have been dire nearly every day. And yet, now the aspen are aglow across Colorado (aside from the ones that are actually burning) and fall is in the air. Can’t stay inside.

In search of a dog-friendly hike where we could see some fall color and escape the smoke, we recently headed south to the Crosier Mountain trails in the beautiful canyon of the North Fork of the Big Thompson River between Loveland and Estes Park, Colorado.

Crosier Mountain framed by aspen
Aspen in October at Crosier Mountain Summit in Northern Colorado

We got what we craved: Blazing aspen, a rigorous hike, dog-friendly trails, and a respite from the smoke that was much more prevalent 20 miles north. Plus, the Crosier Mountain Rainbow trail (one of three that lead to the summit) had fairly light traffic: We encountered a few other parties, but we expected more at the height of the fall color on a Sunday afternoon.

The trail started steep but then leveled off and wound through beautiful forests of pine and aspen. The “Table Rock” outcropping made a good platform to check out the view.

Table Rock on the Crosier Mountain Rainbow trail

The aspen trees were set off dramatically against the pine background. And in the typical Colorado way, the weather took a turn just before we reached the summit, and our descent was marked by a light dusting of snowflakes on the bright carpet of fallen aspen leaves.

Aspen trees ablaze along Crosier Mountain Trail in northern Colorado
Blazing aspen among the evergreens on the Crosier Mountain Rainbow trail

What to expect on the Crosier Mountain hike

Three trails lead up to the peak of Crosier Mountain at 9,250 feet. You can start at Glen Haven (the community), at Garden Gate (a trailhead on County Road 43, also called Glen Haven Road), or at Crosier Mountain Rainbow trailhead, which is a couple of miles past the Garden Gate trailhead. The Rainbow Trail is the steepest. About 2 miles up from the trailhead, it converges with the Glen Haven trail.

Trails converge en route to Crosier Mountain

The Crosier Mountain Rainbow hike is fairly steep to the summit: You’ll gain 2,230 feet in elevation in the four miles from the trailhead to the top. It shifts from a narrow trail surrounded by trees to more open areas with sweeping views.

Crosier Mountain Rainbow trail is fairly steep: You gain 2,230 feet in elevation in the four miles to the top

At the top of Crosier Mountain, you’ll get a panoramic view of Estes Park, Longs Peak, and Twin Sisters Peak.

Weather setting in at the top of Crosier Mountain

Tips for planning to hike Crosier Mountain

  1. Study the entry points. You can get to the summit of Crosier in one of three ways, all accessed from Glen Haven road (County Rd 43) off Highway 34, the main highway between Loveland and Estes Park, Colorado. Glen Haven Road takes you along the North Fork of the Big Thompson River. The Garden Gate trail (#931) is the first trailhead you’ll encounter. It’s a longer trek to the summit but offers a more gradual ascent. The second trailhead, just a couple of miles past Garden Gate, is Crosier Mountain Rainbow Trailhead. The last access point is in the community of Glen Haven, another mile or so past Crosier Mountain Trailhead.
Crosier Mountain Rainbow Trail #981 is steep in places, and is an 8-mile round-trip trek from trailhead to summit and back
  1. Be prepared for changeable weather. The peak of Crosier Mountain is at 9,250 feet, so bring a warm layer and a rain jacket, even if it hasn’t rained for weeks.
  2. Wear decent hiking boots. The trail is steep and rocky, so you’ll be happiest in serious boots rather than trail shoes. I wore lightweight Gore-Tex boots and was glad to have both the ankle support and the rain-proofing.
  3. Bring dogs! This is a great trail for rambunctious dogs, as they can be off-leash as long as they’re under voice control. The trail can be challenging for older dogs: Our 9-year-old Lab was looking fairly stiff on the descent. Don’t forget your poop bags.
Hayley and Lindy pause on the trail carpeted by fallen aspen leaves
  1. Bring plenty of water, especially for dogs. This is a dry trail, so bring plenty of water for yourselves and your dogs.
Bring water for dogs on the hike to Crosier Mountain summit
  1. Consider camping. On the Garden Gate trail, you’ll pass through some wide, grassy meadows that would make for good camping. The options for camping are more limited on the Rainbow trail.
  2. Watch for bears and mountain lions. We saw neither on our hike, but both are common in this area, along with elk and deer.
  3. Check out the regulations. The U.S. Forest Service manages this area, and has web pages for each of the trailheads that lead to the Crosier Mountain Summit. Activities allowed on the trail are hiking, horseback riding, skiing, and biking. No motorized vehicles are allowed. You can download a Forest Service Crosier Mountain info sheet that describes the trail and gives elevation maps here. Here are links to the Forest Service web pages for each trail:
8.
  1. Get there. From Loveland, Colorado, drive west on Highway 34 to Drake, about 8 miles past the Dam Store, and turn right on County Rd 43. The three trailheads for Crosier Mountain are on the left. The Garden Gate trailhead is 2.2 miles from Drake. Crosier Mountain Rainbow is 5.5 miles from Drake, and Glen Haven trailhead is another mile from Rainbow.

Panoramic views at Crosier Mountain

The Crosier Mountain trails are a sweet option for a dog-friendly hike in Northern Colorado with few crowds and a rewarding view from the top. This area’s on our list to check out again this winter, this time on cross-country skis.

Read more about off-river activities