A tour moves through a maintenance tunnel on Dec. 13, 2019, at Hoover Dam. (Ellen Schmidt/Las V …

A tour moves through a maintenance tunnel on Dec. 13, 2019, at Hoover Dam. (Ellen Schmidt/Las V ...

A tour moves through a maintenance tunnel on Dec. 13, 2019, at Hoover Dam. (Ellen Schmidt/Las Vegas Review-Journal) @ellenkschmidt_