Senator Mark Udall is finishing his fifth term as the Representative of Colorado's second district and is a champion of the environment. Sen. Udall earned a 95 percent score from the LCV for his last term in Congress and a 100 percent for every preceding term.

Sen. Udall is a champion of conserving public lands, investing in renewable energy, mandating vehicle fuel efficiency, and addressing global warming. In 2007, Sen. Udall introduced an amendment to the energy bill that would have created a strong renewable electricity standard for America.