sought to block the reopening of the Pinyon Plain Mine (formerly Canyon Uranium Mine). Activity at the mine had ceased in 1992, ten years prior to the moratorium on new development in 2012. Appellants challenged the U.S. Forest Service's consultation process for approving reopening of the mine. As of February 22, 2022, the 9th U.S. Circuit Court of Appeals rejected the arguments in No. 20-16401, concluding that the Forest Service had not acted arbitrarily in making its decision. A study examining samples of groundwater from 180 spring sites and 26 wells in the Grand Canyon region has assessed the presence of uranium in groundwater from September 1, 1981 to October 7, 2020. The goal of the study was to establish a baseline assessment of groundwater conditions in the Grand Canyon region. At 95% of sites, maximum observed uranium concentrations were below the EPAs Maximum Contaminant Level for drinking water, 30 µg/L. At 86% of sites, uranium concentrations were below the Canadian level for protection of freshwater aquatic life, 15 µg/L. South Rim buildings There are several historic buildings located along the South Rim with most in the vicinity of Grand Canyon Village. Buckey O'Neill Cabin was built during the 1890s by William Owen "Buckey" O'Neill. He built the cabin because of a copper deposit that was nearby. He had several occupations such as miner, judge, politician, author and tour guide. This cabin is the longest continually standing structure on the South Rim. It is currently used as a guest house; booking is required well in advance. Kolb Studio was built in 1904 by brothers Ellsworth and Emery Kolb. They were photographers who made a living by photographing visitors walking down the Bright Angel Trail. In 1911, the Kolb brothers filmed their journey down the Green and Colorado Rivers. Emery Kolb showed this movie regularly in his studio until 1976 when he died at the age of 95. Today the building serves as an art gallery and exhibit. The El Tovar Hotel was built in 1905 as a luxury hotel for the Atchison, Topeka, and Santa Fe Railway, on the South Rim near the railway's main line. It was designed by Charles Whittlesley, a staff architect for the railway. The hotel is reminiscent of a Swiss chalet or Norwegian villa, combined with local materials for a rustic appearance sometimes called "National Park Service rustic." It consists of 4 stories, with a