Yucca Mountain is a mentioned only location.
Mr. RADical mentions Yucca Mountain in his journal, explaining that he visited the location overnight to test out the effectiveness of his new radiation suit. He believed that even with high levels of radiation, the test was a success as he didn't feel any adverse effects. Despite the proclaimed success, he did not end up going very deep into the facility as he thought he saw something large moving inside the tunnel.
Yucca Mountain is mentioned in Fallout: New Vegas.