Yellowstone National Park is located in the northwest corner of Wyoming. In summer, all five entrances are open: North: From Livingston and Gardiner, MT, via US 89. West: From West Yellowstone, MT, via US 20 or US 191. South: From Jackson, WY, via US 26, US 89/287/191. East: From Cody, WY, via US 14/16/20. Northeast: From Billings, MT, and Red Lodge via I 94, US 212.