Mark Udall was born in Tucson, Ariz., and now resides in Eldorado Springs, Colo. He earned a bachelor's from Williams College in 1972.
Udall is the son of former U.S. Rep. Morris Udall of Arizona, who was a 1976 candidate for president and helped spearhead some of the nation's landmark environmental laws. Mark Udall's uncle, Stewart Udall, was interior secretary in the Kennedy and Johnson administrations.
Mark Udall was executive director of the Colorado Outward Bound School from 1985 to 1995.
He was elected to the Colorado House in 1996 and to the U.S. House in 1998.
Udall was elected to the U.S. Senate in 2008.
He and his wife, Maggie, have two children.
The Udall family, sometimes called the first family of the West, has been entrenched in politics since the late 1800s. Udalls have served as mayors and judges, as Arizona Supreme Court justices, Cabinet secretaries and members of Congress.
Mark Udall was elected to the U.S. Senate in 2008 after a decade in the U.S. House, but he's been careful not to lean too heavily on the family name.
"The only time it is a burden," he said, "is when people presume all it does is open doors, and people presume I'm only here because of my name."
There are constant reminders of that legacy. Udall is often confused with his cousin, New Mexico Democratic Sen. Tom Udall, who also served in the House and was elected to the Senate in 2008.
Mark Udall's transition to the Senate has been notable for his swift rise in seniority. His state's alphabetical advantage made him the senior member of the 111th Congress' Senate freshmen in 2009, and within weeks of his election he became Colorado's senior senator as well, owing to Democratic colleague Ken Salazar's confirmation as interior secretary.
Udall replaced Salazar on the Energy and Natural Resources Committee, which handles public lands, oil and gas drilling, mining and other issues of special importance to western states. His seniority helped him win the chairmanship of the panel's subcommittee on national parks.
Udall has shown he occasionally will buck his party. He voted against the 2008 financial industry bailout and in support of an amendment to a gun rights bill that would have given the District of Columbia voting rights in the House.
The senator has also clashed with President Barack Obama's administration over indefinite detention of citizens suspected of being terrorists. A member of the Armed Services Committee and the Senate Select Committee on Intelligence, Udall argues that civilian courts are more appropriate.
In a June, 2012, column for CNN.com, Udall wrote, "Inviting our armed forces into our cities and towns with the power to indefinitely detain Americans without trial is a misguided attempt that erodes our rights to due process and limits the effectiveness of civilian law enforcement."
Udall voted in 2010 for the health care reform bill and the overhaul of financial industry regulations. He has said he supports a carbon tax to reduce carbon emissions and slow global warming.
Udall's latest bill would require utilities to generate 25 percent of their electricity from wind, solar and other renewable energy sources by 2025. The Colorado Renewable Energy Standard, first approved by voters in 2004 at the 10 percent by 2020 level, has since been legislatively increased to 30 percent by 2020.
In 2011, Udall led an unsuccessful effort to create a national renewable energy standard. Modeled after a similar law, Udall's bill would have required utilities nationwide to generate 6 percent of their power from renewable energy sources by 2013, followed by gradual increases up to 25 percent by 2025. The bill was recast in 2012, but as of July 2012, the proposal was languishing in the Senate.
Committee Assignments: Armed Services; Energy and Natural Resources; Special Aging; Select Intelligence
American Conservative Union Rating: 5
Americans for Democratic Action Rating: 90
Mark Udall won his June 2014 primary, he will face Cory Gardner in November.
(Last updated by The Associated Press on June 25, 2014.)