Mathews, Mark J.

Mark Mathews' practice concentrates on oil and gas, environmental and land use law.

Mark’s practice involves many of the major disputes facing the energy industry in Colorado. He has successfully represented oil and gas and mining clients in litigation and regulatory rulemakings concerning oil and gas preemption and royalty issues, hazardous waste contamination, enforcement of oil and gas regulations, zoning and development disputes and land use permitting issues.

Mark is outside regulatory and litigation counsel for the Colorado Oil and Gas Association (COGA) and outside litigation counsel for the American Petroleum Insitute (API). Mark also represents many oil and gas companies and energy investment companies in litigation. In 2018 Mark represented COGA, API, Extraction, Martin Marietta Materials and several other energy companies in high profile litigation concerning issues such as operational preemption between state and local governments, challenges to COGCC permits, challenges to state oil and gas regulations and challenges to local government land use permits. In 2016, Mark was the lead attorney representing COGA in litigation that culminated in the Colorado Supreme Court’s ruling striking down Longmont’s ban and Fort Collins’ five-year moratorium on hydraulic fracturing as preempted by state oil and gas law.

In addition, Mark frequently represents his clients before the Colorado Oil and Gas Conservation Commission. Mark has been involved in every major oil and gas rulemaking the last three years on behalf of COGA and individual operators, including rulemakings concerning flowline regulations, setback requirements and financial assurance regulations. Mark also regularly advises energy companies and energy investors on a myriad of issues including potential statewide ballot and legislative measures, state and local government regulations, impacts from high-profile litigation and the potential impacts of state and local political elections.

Prior to joining the firm, Mark was a senior trial attorney in the Environmental Enforcement Section of the U.S. Department of Justice and clerked for the U.S. Court of Appeals for the Tenth Circuit.

In 2018, Mark was one of two Colorado attorneys included in a national list of notable lawyers compiled by the Denver Business Journal and other business journals throughout the country. The list spotlighted “100 executives who are having an impact on business and legal matters across the nation.”

Representative Matters
  • Won a major ruling in Adams County District Court on behalf of client, Colorado Oil & Gas Association (COGA) and the American Petroleum Institute (API). COGA and API jointly filed suit in October to overturn a number of oil and gas regulations adopted by the City of Thornton. Colorado District Court Judge Edward Moss ruled that many of Thornton’s regulations, including its setback regulations, were illegal and operationall preempted by state law.

  • • Successfully represented Extraction Oil and Gas in Boulder District Court against Boulder County’s challenge to Extraction’s leases. The Court ruled against Boulder’s theory that pooling restrictions in the leases precluded Extraction from pooling multiple leases, and held for Extraction on all points of law.

  • Successfully represented the Colorado Oil and Gas Association in litigation against the cities of Lafayette, Fort Collins, and Longmont regarding bans or moratoria on hydraulic fracturing activities, prevailing on summary judgment in each matter. This litigation involved precedent-setting issues pertaining to state versus local preemption of oil and gas activities, and culminated in two rulings by the Colorado Supreme Court striking down Longmont's ban and Fort Collin's five-year moratorium on hydraulic fracturing.

  • Successfully represented COGA and its members in a number of complex, multi-day rulemaking before the COGCC , including rulemakings concerning new setback requirements and new flowline regulations governing mapping, registration, removal and integrity management issues.

  • Represented COGA and its member companies with respect to addressing a variety of legislative issues, including the 2019 omnibus oil and gas bill, statewide ballot measures, and local government regulations.

  • Successfully represented a large oil and gas company in a high profile regulatory proceeding before the Colorado Oil and Gas Conservation Commission regarding potential violations related to the company's deep water injection wells and low-level earthquakes in the region. This work included assisting the company in obtaining permits for new deep water injection wells.

  • Represents a number of oil and gas companies in obtaining state and local government land use and operating permits either through negotiation or litigation. Representation includes assisting companies in royalty, operating, and antitrust disputes with other operators.

  • Represented several energy companies in opposing potential state-wide ballot initiatives impacting oil and gas operations. This work included devising a legal and government relations strategy to oppose twelve different ballot measures.

  • Represents Martin Marietta Materials, the largest aggregate producer in the Western United States, on all land use and environmental issues that arise from its quarrying and manufacturing activities. This work includes representing the company in litigation and administrative proceedings pertaining to alleged air, water and waste violations, as well as zoning and permit approvals.

  • Represents Cotter Corporation, a large uranium production company, in the long-term remediation of its property in litigation actions with private parties, including all issues pertaining to land use and environment, surety and environmental matters. This representation is ongoing and includes successfully defending the company in litigation brought by environmental groups regarding the remediation, negotiating a complex cleanup settlement with federal and state environmental authorities, and overseeing each step of the remediation.

  • Successfully represented a prominent cement company in land use, mining, contract and environmental litigation and land use matters regarding its facilities in Colorado, New Mexico, and South Dakota. This work includes assisting the company in obtaining federal government and tribal approval for a mine and conveyor system on federal and tribal property.

  • Won dismissal on behalf of Gunnison Energy Corporation in a Section 1 and Section 2 gas transportation antitrust case seeking more than $100 million in Federal Court in Denver. Also successfully represented Gunnison Energy in several challenges on state and federal preemption grounds to county regulations governing oil and gas operations, acquisition of mineral assets and defended them in Federal District Court in a challenge to Federal permits for recompleting gas wells.

  • Represented a large development company on the investigation and remediation of soil and groundwater contamination on a 65 acre parcel in the Central Platte Valley and worked closely with the State to obtain approval of Voluntary Clean Up Plans and No Further Action letters for this contaminated and environmentally-sensitive area.

News & Events

Board of Directors, Global Dental Relief

Executive Board, Aurora Economic Development Council

Board of Directors, American Red Cross, Mile High Chapter

Publications & Presentations
  • J.D., with high honors, Stanford Law School
  • B.A., magna cum laude, Yale University
  • Colorado
  • District of Columbia
  • California

Influencers: Law, The Business Journals, 2018

Who's Who in Energy, Denver Business Journal, 2015-2018

Powerbook Top Ten Newsmaker Award, Denver Business Journal

5280 Top Lawyers, Natural Resources – Oil & Gas, 2015-2020

Best Lawyers in America, 2014-2021

Colorado Super Lawyers, 2012-2013, 2018-2019

Chambers USA, 2010-2020

American Red Cross Volunteer Leadership Award, 2017

Editor, Stanford Law Journal

Articles Editor, Stanford Environmental Law Journal


American Bar Association

California Bar Association

Colorado Bar Association

Denver Bar Association

District of Columbia Bar Association