YELLOWSTONE NATIONAL PARK (AP) — Crews are replacing and rerouting a section of the boardwalk in Yellowstone National Park's Black Sand Basin.

Black Sand Basin is a popular geothermal area located in the park's Upper Geyser Basin near Old Faithful. It has more than 300 feet of boardwalk that safely guides visitors through attractions such as Sunset Lake and Rainbow Pool.

However, as the thermal features constantly change underneath Yellowstone, some boardwalks that are placed over their surfaces must be adjusted.