Sandra Zellmer is the Robert B. Daugherty Professor of Law at the University of Nebraska College of Law, where she began teaching in 2003. She is also a co-director of the University's Water Resources Research Initiative, an interdisciplinary educational and research effort.

Zellmer teaches torts, natural resources, water law, environmental law, and related courses. She has published numerous articles and commentary on natural resources law, water conservation and use, and related topics, as well as several books, including Comparative Environmental Law and Natural Resources (Carolina 2013) and Natural Resources Law (West 3rd ed. 2012) (with Professors Laitos and Wood).

Zellmer was appointed as a member of the National Academy of Sciences-National Research Council Committee on Missouri River Recovery and Associated Sediment Management Issues (2008-2010).  In addition to being a Member Scholar of the Center for Progressive Reform, she is also a Senior Specialist (Roster Candidate) with the Fulbright Foreign Scholarship Board, a Member of the Resilience Alliance (an international multi-disciplinary research group that explores the dynamics of adaptive, complex systems), and a trustee of the Rocky Mountain Mineral Law Foundation. Between 2002-2004, Professor Zellmer served as the Chair of the Committee on Marine Resources for the American Bar Association Section on Environment, Energy and Resources, and as an advisor to the Council of Great Lakes Governors Water Working Group Task Force on Tribal/First Nation Treaties in the context of a proposed Great Lakes Water Compact, which was adopted in 2008.

Prior to taking her position at the University of Nebraska, Zellmer was a faculty member at the University of Toledo College of Law from 1998-2003. She has also been a visiting professor at Tulane, Drake, Lewis and Clark, and the University of Auckland law schools. Before she began teaching, Zellmer was a trial attorney for the U.S. Department of Justice Environment and Natural Resources Division, litigating public lands, wildlife and NEPA issues for the National Park Service, Forest Service, Fish and Wildlife Service and other federal agencies. She also practiced law at Faegre & Benson in Minneapolis, Minnesota, and clerked for the Honorable William W. Justice, U.S. District Court, Eastern District of Texas. Her publications cover a range of topics, including preemption, water and public lands management, wildlife and adaptive management, and have been published in journals such as Florida Law Review, Nebraska Law Review, and Houston Law Review.