Anne Castle is a senior fellow at the Getches-Wilkinson Center for Natural Resources, Energy, and the Environment at the University of Colorado Law School, focusing on western water issues, including Colorado River policy and management and Tribal water interests. She is a founding member of the Water Policy Group and Co-Founder of the initiative on Universal Access to Clean Water for Tribal Communities. From 2022 to 2025, she was the U.S. Commissioner on the Upper Colorado River Commission and from 2009 to 2014, she was the Assistant Secretary for Water and Science at the U.S. Department of the Interior. While at Interior, Castle spearheaded the Department’s WaterSMART program and launched the federal Open Water Data Initiative. Castle practiced water law for many years in Denver, Colorado with the Rocky Mountain based law firm of Holland & Hart LLP where she chaired the firm’s management committee and its natural resources department. She currently serves on the boards of the Colorado Water Trust, Stanford University’s Water in the West program, and Colorado Legal Services.