Anchor: Construction on Hoover Dam (originally Boulder Dam, subsequently renamed for the president who authorized the project) began in 1931 in a canyon 45 miles (72 km) southeast of Las Vegas.
Entailed: Hoover Dam was named after the president who made it possible.
Contradiction: The dam has been called Boulder dam ever  since its completion.
Contradiction: Gauve said they traveled north along the defended towns.
Contradiction: Sometimes sensitive subjects get put out for discussion.
Contradiction: The ravine is shallow with sparse vegetation. 
Contradiction: The man is on a two-wheeled vehicle.