Two of America’s richest families kept this Idaho ranch secret for 75 years; now anyone can walk it

It’s now 11,000 acres of open country

Three miles south of Island Park in eastern Idaho, a stretch of land the size of a small city sits inside a volcanic formation called the Henry’s Fork Caldera.

Harriman State Park covers about 11,000 acres of it, right in the heart of the Greater Yellowstone Ecosystem. Mountain meadows roll into lodgepole pine forests.

Willow wetlands line the river corridors. The Henrys Fork of the Snake River winds eight miles through the middle of it all, and from several trails, you can see straight to the Teton Range.

The families who kept this place private for 75 years knew exactly what they had.

Two powerful families ran a private cattle ranch here for decades

Back in 1902, officials from the Oregon Short Line Railroad bought this land, and the Guggenheim brothers picked up shares early on.

For the next 75 years, the Harriman and Guggenheim families ran it as a working cattle ranch and private retreat. People called it the Railroad Ranch.

Then on April 1, 1977, the families donated the whole property to the State of Idaho, with one condition: keep it as a wildlife refuge.

The park opened to the public in 1982, and the donation helped create Idaho’s Department of Parks and Recreation.

Fly fishers call the Henrys Fork stretch simply “the Ranch”

The eight miles of the Henrys Fork running through the park go by one name among anglers worldwide: “the Ranch.” The river here runs wide, shallow and clear, fed by springs that keep it cold.

Rainbow trout grow large in this water, and they are famously picky eaters. You fish catch-and-release only, with barbless hooks and flies, from June 15 through Nov. 30.

People travel from around the world to try their luck, and the trout win more often than you’d think.

Eight-foot wingspans glide over Silver Lake

Trumpeter swans winter here, and they are the largest native waterfowl in North America. Their wingspans stretch up to eight feet.

Silver Lake is where they nest, and you can watch them from the trail along the shore. Over at Golden Lake, young swans that haven’t paired off yet gather during molting season.

Beyond the swans, you’ll find elk, moose, sandhill cranes, mule deer, coyotes and bald eagles moving through the park. Black bears and grizzly bears pass through from time to time too.

Twenty miles of trails loop past lakes and old ranch buildings

More than 20 miles of trails cut through the park for hiking, mountain biking and horseback riding, though some close seasonally to protect wildlife.

The Ranch Loop takes you past historic buildings and along the Silver Lake shoreline, which makes it the go-to route for spotting animals.

If you’re into birding, the Silver Lake Loop circles one of the park’s best lakes for it. Come fall, the Meadow Loop draws visitors who want to hear bull elk bugling during the rut.

Golden Lake sits in a meadow full of wildflowers and elk

The Golden Lake Loop takes you deeper into the park, through meadows thick with wildflowers in a semi-wilderness setting. Trumpeter swans float on the water while elk graze the shoreline.

Keep in mind that several trails close for wildlife protection in spring and early summer. In 2026, the John Muir, River, Big Bend, East Gate and North Gate trails close April 15 through June 15.

Ridge Trail and Ridge Shortcut stay closed until July 1. The trails range from easy to moderate, so families and experienced hikers both have options.

Lupine and paintbrush fill the meadows by mid-June

When June and July hit, the sage meadows and pastures light up with lupine, Indian paintbrush and arrowleaf balsamroot.

You walk through wetlands, then forest, then open meadow, and the landscape shifts with every stretch of trail. Morning and evening are the hours to be out if you want to spot elk, deer and moose feeding in the open.

The park sits at about 6,100 feet, which keeps summer temperatures comfortable.

Photographers find a different shot around every bend, from wildlife to mountain backdrops to the river.

Ride the same trails the ranch cowboys used

Guided horseback rides run from June 1 through Oct. 31, and you can pick a one-hour, two-hour or half-day trip through the meadows and forests.

The trails follow the same routes that ranchers and cowboys rode for decades when this was a working cattle operation. If you want to cover more ground without wearing out your legs, this is how to do it.

Book an early morning ride in the fall, and you may find yourself on horseback near bugling elk during the rut.

All 27 original ranch buildings are still standing

Every one of the 27 Railroad Ranch buildings remains intact, from the cookhouse to the horse barn.

You can walk through the Harriman cottage, built around 1911, the bunkhouse, the dining cottage and the ranch manager’s house.

During summer, ranger-led tours of the buildings typically run on weekends and holidays, but check with the park to confirm the current schedule.

The buildings are furnished and kept up to reflect the working ranch days. If you’d rather go at your own pace, grab a self-guided tour brochure from the visitor center.

Winter turns the park into 20 miles of groomed ski trails

Once the snow hits, the park grooms more than 20 miles of trails for classic and skate skiing. You can also snowshoe or fat bike on marked routes.

Trumpeter swans, bald eagles and other wildlife stay active along the Henrys Fork through the cold months, so you’ll share the trails with more than just other skiers.

The park runs educational programs on Saturdays all winter long.

Kids can pick up self-guided Junior Ranger and Junior Snow Explorer Backpack activities any day of the week.

Sleep in a yurt by the lake or rent the ranch manager’s house

You won’t find traditional tent or RV camping here, but the overnight options are worth a look.

Yurts near Silver Lake sleep up to six and come with a wood stove, bunk beds and a propane cooking stove, though you need to bring your own bedding. They’re open year-round.

If you’ve got a bigger group, the four-bedroom Ranch Manager’s House, three-bedroom Cattle Foreman’s House and the Railroad Ranch Dormitory and Dining Hall all take reservations.

The dormitory fits 15 to 36 overnight guests, with dining space for up to 38. One rule to know: dogs can’t go on the trails and have to stay leashed in the parking lots.

A 114-foot waterfall drops just down the road

The Mesa Falls Scenic Byway runs about 30 miles between Ashton and the Island Park area along Idaho Highway 47, cutting through the Caribou-Targhee National Forest.

The road leads you to Upper and Lower Mesa Falls on the Henrys Fork. Upper Mesa Falls drops about 114 feet and stretches roughly 200 feet wide.

Lower Mesa Falls pours 65 feet over a basalt cliff.

These are among the last major undisturbed waterfalls left in Idaho, and Harriman State Park co-manages the Mesa Falls Recreation Area with the U.S. Forest Service.

Visit Harriman State Park in Idaho

You’ll find Harriman State Park at 3489 Green Canyon Road in Island Park, Idaho, about 28 miles south of West Yellowstone, Mont., and roughly 130 miles north of Pocatello.

The park stays open year-round, with day-use areas running from 7 a.m. to 10 p.m. The motor vehicle entrance fee is $7 per vehicle.

If you come in winter to ski or snowshoe, you’ll also need a Winter Access Pass on top of the vehicle fee. Check the official website for overnight reservations and current conditions before you go.

This article was created with AI assistance and human editing.

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