We had a really nice weekend trip to Woodbine in Montana. It's a large (by MT standards) USFS campground about 45 miles south of Columbus, MT (which is on I-90). It's a beautiful area, and a really nicely kept campground with well spaced sites. Each site has its own bear box, which makes it handy to store the grill and garbage. It sits on the edge of the Absaroka-Beartooth wilderness and there are some nice hikes in the area. Worth a visit if you're passing through.