Baker Pass crosses the Continental Divide through the Never Summer Mountains and into the Michigan River drainage to the west of Mount Nimbus—a drainage that feeds streams and rivers that drain into the Gulf of Mexico. Other mountain passes are La Poudre Pass and Thunder Pass, which was once used by stage coaches and is a route to Michigan Lakes. Little Yellowstone has geological features similar to the Grand Canyon of the Yellowstone. The Green Mountain trail once was a wagon road used to haul hay from Big Meadows. Flattop Mountain, which can be accessed from the eastern and western sides of the park, is near Green Mountain. Shadow Mountain Lookout—a wildfire observation tower—is on the National Register of Historic Places. Paradise Park Natural Area is an essentially hidden and protected wild area with no maintained trails penetrating it.