Maggie is a veteran of numerous local, state, national and international environmental, political, legal and policy campaigns. She is past President and CEO of the Climate Reality Project and the Climate Action Fund. She was the President of America Votes as well as the Southwest Regional Director and Deputy Executive Director of the Sierra Club. Maggie currently serves on the boards of the Green Fund, the Energy Future Coalition, and the Colorado State University School of Global Environmental Sustainability.

Maggie began her career as a classroom teacher and community organizer on the Navajo and Hopi Reservations. An avid outdoorswoman, she worked with Outward Bound Schools and participated in numerous mountaineering and other outdoor expeditions around the world. She and her husband, Mark Udall, live in Eldorado Canyon, Colorado. They have two children.