Jacky Rosen and Catherine Cortez Masto want to ensure that Yucca Mountain never serves as a nuclear waste dump site. Members of a congressional tour make their way through the north portal of Yucca Mountain near Mercury on Saturday, July 14, 2018. Jacky Rosen and Catherine Cortez Masto want to ensure that Yucca Mountain, located about 60 miles northwest of Pahrump, never serves as a nuclear waste dump site. Nevada has long opposed using Yucca Mountain to store nuclear waste. “While I welcome the Trump administration’s recent move to leave the unworkable Yucca Mountain proposal behind, we cannot take anything for granted.”