Big Timber KOA Campground encourages you to relax under big trees with grass sites where the prairie meets the mountains. Fish at nearby Boulder or Yellowstone rivers. Receive a 20 percent discount at Montana's water park, Big Timber Waterslide, next door. A pool, mini golf, and a restaurant are all nearby our tent and RV sites. Also wireless Internet service is available. This is your stay and play location. We offer Value Card KOA discounts.