Access to Yellowstone National Park’s Black Sand Basin will be temporarily closed while maintenance crews replace and reroute a section of boardwalk that has been damaged by the area’s thermal features. Black Sand Basin, a popular geothermal area located in the park’s Upper Geyser Basin near Old Faithful, has more than 300 feet of boardwalk that safely guides visitors through attractions such as Sunset Lake and Rainbow Pool. However, Park Spokesman Al Nash explains that as the “plumbing” underneath Yellowstone’s thermal features constantly changes, so too must the boardwalks that are carefully and strategically placed over their surfaces. Nash says crews anticipate having the work completed soon after Memorial Day. Nash says the temporary closure includes the entire boardwalk around the basin as well as the associated public parking area. Trails leading into the basin will also be signed and marked to protect visitors.