Nine days after the Boulder Dam Hotel closed for lack of funds, an anonymous donation of $260,000 has made it possible for the historic structure, its museum and restaurant to reopen. “I’m so thrilled with this,” said attorney Ralph Denton, who brokered the donation to the hotel. He presented a check to Darryl Martin, president of the Boulder City Museum and Historical Association at 2 p.m. Monday in front of the hotel. The historical association operates the hotel and restaurant to support the museum.