The Laurance S. Rockefeller Preserve is a 1,106 acres refuge within Grand Teton National Park on the southern end of Phelps Lake, Wyoming. The site was originally known as the JY Ranch, a dude ranch. Starting in 1927, John D. Rockefeller Jr. purchased much of the land in Jackson Hole for the creation of Jackson Hole National Monument and the expansion of Grand Teton National Park. But he retained the 3,100-acre JY Ranch as a family retreat.