Henry's Lake State Park

Henry’s Lake State Park sits at 6,400 feet elevation in the Island Park region of eastern Idaho, about 15 miles west of Yellowstone National Park. The lake itself covers roughly 6,000 acres and is consistently ranked among the best trout fisheries in the American West. The park is small and focused, with camping and fishing as its core purposes rather than an extensive trail system. If you are coming here, you are almost certainly coming to fish.

Fishing Henry’s Lake

The lake is legendary for its cutthroat trout, brook trout, and cutbow/rainbow-cutthroat hybrid trout. The cutbow hybrid, a cross between Yellowstone cutthroat and rainbow, grows unusually large in these cold, productive waters, and fish in the three to five pound range are caught regularly. The Idaho Department of Fish and Game manages the fishery actively, and catch-and-release is common practice among anglers who want to preserve what makes the lake exceptional.

Fishing access is available from shore, but most serious anglers fish from boats or float tubes to reach the weed beds and drop-offs where larger fish hold. The park has a boat launch facility. Motorized boats are permitted, though many anglers use small craft to avoid disturbing the surface. Fly fishing is popular from late spring through fall, with the best action typically in September and October when the crowds thin and the fish feed aggressively before winter.

Idaho fishing licenses and applicable stamps are required. Check current regulations with Idaho Fish and Game before your trip, as rules can change between seasons.

Camping at Henry’s Lake

The campground has sites for both tents and RVs, with electrical hookups available in some sites. The setting is open and high, with views across the lake toward the Continental Divide. Nights are cold even in midsummer at this elevation, so bring warm layers regardless of the time of year. A camp host is typically on site during the main season.

Reservations are strongly recommended from mid-June through Labor Day, as the park fills quickly during peak fishing season and holiday weekends. The campground includes restrooms and access to the boat launch. The RV dump station is closed for the 2025/2026 season; the only sewage dump availability at the park is through full-hookup sites.

The Surrounding Island Park Region

The park makes a practical base for exploring the broader Island Park plateau. Yellowstone’s west entrance at West Yellowstone, Montana, is roughly 20 miles to the east. Harriman State Park, known for its wildlife viewing and fly fishing on the Henry’s Fork of the Snake River, is about 20 to 25 miles to the south. The Mesa Falls Scenic Byway and Targhee National Forest offer additional hiking and sightseeing within a short drive.

The lake sits in a high mountain basin that sees significant snowfall. Henrys Lake State Park is currently open and accessible in winter, with roads and parking lots maintained; winter services may be limited and visitors should confirm current conditions before traveling. Confirm access dates with Idaho State Parks before planning an early or late-season visit.

Pet Policy

Pets are welcome at Henry’s Lake State Park but must be kept on a leash no longer than six feet at all times. This applies to campgrounds, the shoreline, and all other areas of the park. Pets are not permitted in swim areas or park buildings. Given the presence of bears and other wildlife in the area, keeping pets leashed and close to camp at all times is important for their safety as well as for compliance with park rules.

Wildlife to Be Aware Of

The park sits within one of the most wildlife-rich corridors in the lower 48 states, and visitors should take that seriously.

Grizzly bears are present in the Island Park region and are occasionally seen near the park. This is an active grizzly population connected to the Greater Yellowstone Ecosystem. Carry bear spray whenever you are away from your vehicle, store food and scented items in bear boxes or hard-sided vehicles, and never leave food unattended at your campsite. Learn how to use your bear spray before your trip.

Black bears are also common throughout the area. They are attracted to food, garbage, and anything with a scent. The same food storage practices that apply to grizzlies apply to black bears. Do not assume a smaller bear is less of a concern.

Moose are frequently seen along the lakeshore and in the marshy areas around Henry’s Lake. They look slow and calm but are unpredictable, especially cows with calves in spring and bulls during the fall rut. Give any moose you encounter a wide berth and do not approach for photographs. A moose can cover ground quickly when it decides to charge.

Rattlesnakes may occur in parts of eastern Idaho, but their presence around Henrys Lake State Park should be confirmed with park staff before being presented as a park-specific warning.

Practical Information

Henry’s Lake State Park is located off U.S. Highway 20 near the town of Island Park, Idaho, approximately 100 miles northeast of Idaho Falls. The park entrance is near U.S. Highway 20 milepost 401. The nearest services including gas, groceries, and lodging are available in Island Park and in West Yellowstone, Montana, about 20 miles to the east.

The day-use fee is $7 per motor vehicle. Camping fees vary by site type and whether electrical hookups are included. Idaho residents may benefit from the Idaho State Parks Passport, which is $10 per vehicle per year and covers day-use access; out-of-state frequent visitors can purchase an annual Motor Vehicle Entry Fee sticker. Camping reservations can be made through the Idaho State Parks reservation system at getoutside.idaho.gov or by calling 1-888-922-6743. The park is currently open and accessible year-round, though services vary seasonally and winter visitors should confirm current conditions and reservation availability.