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Rocky Mountain National Park

Rip & Go: Tonahutu Loop – Rocky Mountain National Park, CO

Cross elk-filled woods and bighorn- busy flats on this park's quiet side.

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View of 12,274-foot Snowdrift Peak (Casey Lyons)


View From Flattop (Deborah Stanley)

Do it

If locals say “Go high or go home” is this park’s unofficial motto, then this 25.2-mile tunda-topped loop is its poster child. Park at the Tonahutu/North Inlet trailhead (1) on RMNP’s less-trafficked west side, and go north on the Tonahutu Trail. Hike along lodgepole pine-lined trail to the junction with the Tonahutu Spur Trail at .8 mile (2). Ramble beside Tonahutu Creek to where the forest thins at mile 3.2. Big Meadows, a two-mile-long field flanked by spruce and filled with a dozen varieties of wildflowers (bloom starts in July) stays hidden until after the junction with the Green Mountain Trail (3).

In 1.7 miles, pass Sunset campsite (4), and, permit willing, continue 3.6 miles past seven more campsites and 30-foot Granite Falls (5), to Hynach llama camp, via a .4-mile hike on the Hynach Lakes Trail (6). Located at 10,707 feet in a pine-bottomed valley, this campsite (7) offers a surround-sound wilderness experience—a rushing stream, yipping coyotes, and bugling elk.

Return to the Tonahutu Trail junction early the next morning (by 7 a.m.) to avoid summer’s afternoon thunderstorms on the exposed alpine miles ahead, and ascend across granite talus to Bighorn Flats. Mountain views open to the west on this treeless slope. Climb toward Ptarmigan Point (12,363 feet) on the Continental Divide. At the Flattop Mountain Trail junction (8), drop your pack and hike to the rock- lined rim at Flattop’s 12,324-foot summit above Emerald Lake (“See This”).

The trail continues south past knee-high cairns with eastern views of 14,259-foot Longs Peak. At mile 15.7, descend 1,400 feet in 1.3 miles on switchbacks to Hallett Creek (9). Continue down with occasional views of 12,324-foot Ptarmigan Mountain. After North Inlet Junction campsite (10), there’s a second string of camps. Aim for the dispersed zone south of 60-foot Cascade Falls (11). The next day, knock off the final three miles between high and home.

Trip Planner

Get there From Granby, take US 34 east for 15.8 miles.


Gear up Rent bear canisters (required, $5/day) at Never Summer Mountain Products. 919 Grand Lake Ave., Grand Lake. (970) 627-3642

Permit $20/trip. Reserve by phone (970-586-1242) March 1 to May 15. Reserve by mail or in person May 16 to October 1.


Trip hikes/1049789

Key Skill:
Using a bear canister 

The park requires countermeasures to keep resident black bears from becoming habituated to human food. Use this guide to load, haul, and store a canister properly.

Load Bear canisters are generally smaller than the stuffsacks you may be used to. Keep yours organized by layering meals in reverse order (last meal first). The first day’s food doesn’t need to fit inside.

At night: Save room for smellables (including toiletries, sunscreen, and bug spray—double-bagged in zip-tops to prevent food-contaminating spills).

On the trail: Remove snack items to keep them handy, and pack the canister against your back toward the middle of the pack for the easiest carry.

Leave Pick a spot 70 steps downwind from your (or anyone else’s) campsite. Set the canister in a flat area with a safe runout (avoiding spots near cliffs, steep slopes, and rivers so the canister doesn’t roll out of reach if a bear decides to bat it around). Don’t pin the canister between rocks or the arms of a fallen tree, which could enable a bear to lever off the top.

Food Choose grub that won’t damage easily when crammed. General tips: Squeeze all of the air out of zip-top bags before packing to avoid their popping open. Freeze-dried trail meals pack tighter vertically than they do horizontally. Don’t fold tortillas; curve them against the edge.

See This: Glaciation Line

Flattop Mountain (mile 13.9) offers one of the park’s best views of the contrast between glacially carved terrain (east of the Continental Divide) and mountains the earth-shaping ice floes never touched (low-sloped tundra to the west). Beginning about 15,000 years ago, the dual processes of plucking (snatching up boulders) and abrasion (sanding off bedrock), carved the steep amphitheaters to the east (pictured), often leaving behind remnant snowfields and tiny alpine lakes.

Locals Know

The Tonahutu Trail (this trail’s first leg) is the final section of a little-known back way to the 14,259-foot summit of Longs Peak. The 42.4-mile Rocky Mountain Grand Loop departs from Grand Lake on the East Inlet Trail. Cross the Continental Divide at the Boulder-Grand Pass (12,061 feet) and aim for Thunder Lake for the first night’s camp. Bushwhack northwest toward Lion Lake No. 1, and routefind toward North Ridge, heading just south of Castle Lake. Gain Longs’ summit ridge via Keplinger Couloir, and join the famous Keyhole Route for 300 slow-going and slabby vertical feet, called the Homestretch, to the top. Descend among the peak-bagging throng to Glacier Gorge (night two), via the North Longs Peak Trail, then swing west back over the Divide on the Flattop Mountain Trail, and close the loop on the Tonahutu Trail. Download GPS data at

On The Menu

Breakfast 1

On the road

Lunch 1

Bagels with avocado and Havarti

Dinner 1

Tonahutu Tuna

Breakfasts 2 & 3

Granola with dried blueberries and milk

Lunch 2

Bagels with PB & J

Dinner 2

Switchback Chicken


Yogurt-covered pretzels

Tonahutu Tuna

Surf for your turf

2 cups egg noodles

16-ounce pouch tuna

1⁄4 cup potato leek soup mix

1⁄2 cup broccoli, chopped

4 tablespoons dried onions

1⁄4 cup dried milk

Cheddar, cubed

Cook egg noodles until nearly al dente. Add broccoli and boil until tender. Drain, but reserve 1⁄2 cup water in the pot. Add potato leek soup, dried milk, and onion, and stir. Top with Cheddar. Serves two.

Switchback Chicken

Protein-packed for recovery

2 cups instant grits

1 pack dried mushrooms, sliced

1/8 cup dried onion

1 red pepper, chopped

17-ounce pouch chicken

1 tablespoon olive oil

Cheddar, cubed

Sauté red pepper in olive oil until soft. Add three cups water, dried mushrooms, and onions. Bring to a boil and add grits and chicken. Stir continuously until grits are soft (five minutes). Top with cheddar. Serves two.

The Grocery List (Aisle # in Nearest Store Below)

[ ] avocado (produce)

[ ] broccoli (produce)

[ ] red pepper (produce)

[ ] dried mushrooms (produce)

[ ] PB&J(1) [ ] 8 oz. Cheddar (1)

[ ] sliced Havarti (1)

[ ] dried onion (2)

[ ] dried blueberries (2)

[ ] bagels (2)

[ ] tuna pouch (3)

[ ] potato leek soup (3)

[ ] chicken pouch (3)

[ ] egg noodles (4)

[ ] energy bars (5)

[ ] granola (6)

[ ] dried milk (6)

[ ] instant grits (6)

[ ] yogurt pretzels (8)

Pack Olive oil

PIT STOP The breakfast buffet at the Fat Cat Café provides a full spread of eggs, sausage, bacon, pan- cakes, coffee, juices, and pie. 916 Grand Ave., Grand Lake, CO; (970) 627-0900

NEAREST GROCERY STORE CITY MARKET 1001 Thompson Rd., Granby, CO (970) 887-7140

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