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.
The facts
Season: May — USDA Forest Service, Aug 24, 2026
21 bookable sites
56 sites in total, including non-bookable
Vehicles up to 50 ft
Up to 150 people per site
Loops: B, BUTTERMILK, MANAGEMENT SITES
Site types
35 Management
19 Standard Nonelectric
1 Group Standard Nonelectric
1 Standard Electric
Amenities
✓ Electric hookups
✓ Water hookups
✓ Campfires allowed
✓ Shade
✓ Pets allowed
Not recorded upstream: sewer hookups, fire pits, picnic tables, grills.
From West Yellowstone, Montana, take Highway 20 south, southwest for approximately 25 miles and from Ashton, Idaho, take Highway 20 north for approximately 27 miles.
Turn west onto the Kilgore-Yale Road #030 (across from Elk Creek Gas Station) and go about 2 miles to the Buttermilk Loop Road #126. Turn onto #126 and go approximately 3 miles to an intersection where you will see the campground sign just off the right side of the road. The road will split ahead, with boat ramp and group area on the left, and the single loops to the right.
1991–2020 averages from the nearest NOAA station, 2 mi away — not measured at the facility itself, and elevation can make a real difference over that distance.
Map
Fees and stay limits
Group Site Fees: $65.00 per night Sunday through Thursday and $130.00 per night Friday and Saturday. A weekly rate is not available.
From Recreation.gov, which is not always current. The operator's own page is the authority on what you will be charged.
More photos
Member photos
Common questions about Buttermilk
Can you reserve a site at Buttermilk?
Yes, Buttermilk is reservable through Recreation.gov.
How many campsites does Buttermilk have?
56 sites in total, of which 21 can be booked.
What is the maximum RV length at Buttermilk?
50 ft. That is the longest vehicle the sites here are recorded as taking; individual sites may be shorter.
Are pets allowed at Buttermilk?
Yes, pets are allowed at Buttermilk.
Does Buttermilk have hookups?
Electric, Water.
Are campfires allowed at Buttermilk?
Campfires are allowed at Buttermilk. Check for a current fire restriction before you go.
Also listed by
Buttermilk also appears in other federal recreation data. Facts below are matched by name and location, not confirmed by Buttermilk's operator.
USDA Forest Service — data as of Aug 24, 2026
Single Site $ 25.00
Double Site $ 50.00
Group Area (Sun.-Thurs.) $ 100.00
Group Area (Fri.-Sat.) $ 200.00
Extra Vehicle (ea.) $ 7.00
Restrictions:
No All Terrain Vehicles (ATVs) or Off-HighwayVehicles (OHVs) allowed in the park.
Comments