USDA Forest Service · Idaho

Buttermilk

USDA Forest Service · Idaho, United States

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Sites
56
Hookups
1 electric, 2 with water, 20 no hookups
Season
May 22 to September 15
Max RV length
50 ft
Group sites
Yes
Drinking water
Yes
Restrooms
Yes
Pets
Yes
Elevation
6,335 ft
Dark sky
Bortle class 1
Cell coverage
AT&T weak · Verizon weak · T-Mobile good (carriers' 4G LTE filings to the FCC, 2025-12; not measured here)
Access road
BUTTERMILK CG (NFSR 20337) · asphalt · high degree of user comfort
Lake
Caribou-Targhee National Forest
Nearest town
ISLAND PARK
Address
BUTTERMILK LOOP RD, ISLAND PARK, ID, 83429
Phone
208-558-7658 OR 208-270-0094
Activities
Camping, Fishing, Hiking, Hunting, Mountain Biking, Rafting, Water Skiing, Wildlife Viewing

55 numbered sites are mapped one by one - open the site map to pick yours.

About

Overview

Buttermilk Campground is located approximately 30 miles southwest of West Yellowstone, Montana and 32 miles north of Ashton, Idaho in beautiful Island Park, Idaho.

Buttermilk sits next to Island Park Reservoir at an elevation of 6,200 feet. Visitors love Island Park for its world-class fishing and outstanding scenery and wildlife viewing opportunities.

Recreation

The Island Park area is prized for its fishing; the Henry's Fork is known as one of the nation's best fly-fishing streams. Anglers cast for rainbow, cutthroat and brook trout and Kokanee salmon.

Island Park Reservoir offers boating, water skiing and excellent fishing opportunities. The reservoir is used for irrigation so the water level recedes throughout the summer, but is generally useable all season. Henry's Lake is nearby.

Hiking, biking, horseback riding and ATVing are popular activities. Many miles of trails are in the area, including the Continental Divide National Scenic Trail and the Nez Perce Trail.

The Big Springs National Recreation Water Trail offers an approximately three-hour float or canoe trip through beautiful scenery. Wildlife, including moose, bald eagles and Sandhill cranes, are often seen along the trail.

Facilities

The campground contains two loops for single family camping and one loop for group camping, with a total of 55 sites. The large group site can accommodate up to 150 people. Site 038 has 15-amp electric hookups.

Vault toilets and drinking water are provided. A concrete boat ramp with docks is located between the group camping and single family camping loops. Access to the campground is on a paved road but the interior loop roads and parking spurs are gravel.

Natural Features

Island Park is composed of two areas of extinct volcanic activity. The Henry's Fork Caldera sits inside the larger Island Park Caldera. The area is known for its dense forests of lodgepole pine, broad grassy meadows bursting with summer wildflowers and a wide variety of wildlife, including black and grizzly bears, moose, elk, deer, bald eagles, Sandhill cranes and much, much more.

The campground is situated in a forest of lodgepole pine, which provides partial shade in some sites. Some areas of the campground are more open and sunny than others.

Nearby Attractions

Mesa Falls Scenic Byway is 13 miles south of the campground. This 28-mile road leads to scenic overlooks and trails at 110 foot Upper Mesa Falls and 85 foot Lower Mesa Falls.

Harriman State Park is 15 miles south. The Henry's Fork meanders through the Harriman, offering excellent fishing. Over 20 miles of trails are available, and wildlife is abundant in this scenic park.

Henry's Lake State Park is 18 miles north, offering fishing, a fish cleaning station and boat ramp.

Yellowstone National Park's west entrance is just 29 miles north in the town of West Yellowstone, Montana. Visitors enjoy day-tripping to the park for unparalleled wildlife viewing and the beautiful and unique scenery.

Fees

Group Site Fees:

$65.00 per night Sunday through Thursday and
$130.00 per night Friday and Saturday. A weekly rate is not available.

Weather, month by month

MonthTypical highTypical lowColdest nightHottest dayYears with a night below 32°F
January24°10°-17°36°11 of 11
February26°13°-14°42°11 of 11
March37°21°6°52°11 of 11
April41°25°1°59°11 of 11
May57°31°25°69°11 of 11
June68°44°32°84°2 of 11
July81°53°41°90°0 of 11
August80°52°45°89°0 of 11
September69°44°33°79°0 of 11
October51°32°8°70°8 of 10
November36°21°-4°55°10 of 10
December26°11°-3°37°10 of 10

Mid-month figures from 2016–2026 of daily weather at this spot (ERA5 reanalysis via Open-Meteo, CC BY 4.0), in °F. Typical is the median; coldest and hottest are the extremes seen.

Nearby campgrounds

All public campgrounds in Idaho · Every state and province · Facts read from the operator 2026-02-25. Confirm fees, rules and current status with the operator before you go.