From Dillon, MT, take US Rt. 15 south 18.1 miles to State Rt. 324 (Exit 44). Take Rt. 324 west for 19.7 miles to campground sign. Turn right at sign onto gravel road and, following signs, go 21.1 miles to another campground sign. (This is Forest Rt. 181, but it is not marked at turn.) Turn right into campground.
It's really good, I definitely recommend it, it really feels like I'm traveling the world.
Great place to camp and the fishing is good if you know what you're doing.