Fire mapping of the Lone Star Fire south of Old Faithful in Yellowstone National Park calculated the size of the fire now at 763 acres. The fire was discovered Saturday evening after a lightning storm had moved through the area. Fire crews are currently working to suppress the fire. While the Old Faithful developed area and West Thumb Geyser Basin remain open, the Grand Loop Road, south of Old Faithful between Old Faithful and West Thumb Junction, is closed. Trails and campsites in the Shoshone Lake and Lone Star Geyser area are also closed.