YELLOWSTONE NATIONAL PARK, Wyo. » A popular trail in Yellowstone National Park has been closed because of new geothermal hot spots that could endanger hikers.

Park officials said Wednesday that geologists will use thermal imaging, temperature readings and a ground survey to examine hot spots on the Clear Lake Trail.

The 1.5 mile-trail overlooks the Upper and Lower Falls in the Grand Canyon of the Yellowstone.

Three other Yellowstone trails have reopened after repairs: a boardwalk in the Back Basin of the Norris Geyser Basin, Uncle Tom's Trail on the South Rim of the Grand Canyon of the Yellowstone and the Wraith Falls Trail.