Mary Slosson
Associate
Mary Slosson is an associate in the Environmental & Public Lands Group at Davis Graham & Stubbs LLP. Her practice focuses on environmental litigation, compliance, and due diligence, with experience in matters involving the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the Resource Conservation and Recovery Act (RCRA), and the Clean Water Act (CWA). She assists clients in the mining, oil and gas, real estate development, and manufacturing industries, helping them navigate environmental disputes and regulatory issues involving contaminated properties, hazardous and solid waste, water quality, and cleanup obligations.
Mary has worked on complex environmental litigation matters involving corporate successor liability, historical ownership and operations, and allocation of responsibility for environmental impacts. She also assists clients with environmental compliance and transactional diligence, including the legal sufficiency of Phase I Environmental Site Assessments under the ASTM E1527 standard. Her appellate clerkship experience informs her legal analysis, issue-spotting, and written advocacy in matters involving technical facts, evolving regulatory requirements, and significant environmental risk.
Before joining Davis Graham, Mary served as an appellate law clerk to Justice Maria Berkenkotter of the Colorado Supreme Court. She earned her J.D. from the University of Colorado Law School, where she was an associate editor of the University of Colorado Law Review, published a law review note on the Law of the Colorado River, and worked as a legal writing teaching assistant. Her legal experience during law school included work with Denver Water’s Office of General Counsel, the Natural Resources and Environment Section of the Colorado Attorney General’s Office, Justice Melissa Hart of the Colorado Supreme Court, and Judge Todd Taylor of the Division 1 Water Court.
Prior to law school, Mary spent a decade working as a print journalist, reporting for news agencies across the American West. She brings newsroom-honed fact development, clear writing, and deadline discipline to her client work.
Mary is admitted to practice in Colorado and in the U.S. District Court for the District of Colorado.
MEMBERSHIPS & AFFILIATIONS
- American Bar Association, Member of the Section of Environment, Energy, and Resources
- Colorado Bar Association, Environmental Law and Water Law Sections
- Colorado Women’s Bar Association
- Denver Bar Association
- Foundation for Natural Resources and Energy Law
PUBLICATIONS & SPEAKING
- Davis Graham Legal Alert, Colorado Supreme Court Confirms Water Activity Enterprises May Exercise Eminent Domain Authority for Water Delivery Infrastructure, with Theresa Wardon Benz & Sarah Kellner, (May 2026)
- Davis Graham Legal Alert, Colorado Court of Appeals Holds That Local Governments May Impose Impact Fees on Replacement Construction Projects, with Theresa Wardon Benz & Addison May Zahn (May 2026)
- Davis Graham Legal Alert, Colorado Supreme Court Broadens Protections for Public Works Subcontractors, with Theresa Wardon Benz & Caitlin Dacus, (April 2026)
- Davis Graham Legal Alert, Colorado Court of Appeals Holds That Federal Law Preempts State Courts from Ordering Airport Noise Restrictions, with Theresa Wardon Benz & Christopher W. Dan, (March 2026)
- “Force Majeure and the Law of the Colorado River: The Confluence of Climate Change, Contracts, and the Constitution,” 95 Colorado Law Review 709 (2024)
- “Will Gen Z Change the Way We View Water Issues?” Invited panelist, Colorado Water Congress, Jan. 11, 2024, Aurora, Colorado.
Practices & Industries
Admitted In
Colorado
Education
University of Colorado Law School, J.D., 2024
University of Southern California, M.A., 2012
University of Virginia, B.A., 2008