The Greater Yellowstone Coalition is a conservation organization protecting the lands, waters and wildlife of the 20-million-acre (81,000 km2) Greater Yellowstone Ecosystem of Idaho, Montana and Wyoming. The group was formed in 1983 with the idea that protecting Yellowstone and Grand Teton national parks could only be achieved by protecting the wild integrity of the last largely intact temperate ecosystem in North America. The group is based in Bozeman, Montana, and has offices in Idaho Falls, Idaho, Jackson, Wyoming and Cody, Wyoming.