Mathews, Mark J.

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

Mark’s practice involves nearly all 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 and disputes 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, aggregate and cement companies and energy investment companies. In 2018 Mark represented COGA, API, Extraction, Martin Marietta Materials and other energy companies in high profile litigation concerning issues such as operational preemption between state and local governments, challenges to COGCC permits and challenges to local government land use permits.

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. He has also recently been involved in high-profile state rulemaking including the flowline regulations recently implemented by the Colorado Oil and Gas Commission. Mark 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.

In addition, Mark frequently represents his clients in administrative proceedings before the Colorado Department of Public Health and Environment, the Colorado Oil and Gas Conservation Commission (COGCC) and the Colorado Public Utilities Commission. Mark has successfully negotiated many favorable settlements for corporations and private landowners throughout the West.

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). A Colorado District Court ruled that the City of Thornton illegally passed oil and gas regulations last year that conflicted with state and federal law. COGA and API jointly filed suit in October to overturn the regulations. Colorado District Court Judge Edward Moss relied on the 2016 state Supreme Court rulings which culminated in the Colorado Supreme Court’s ruling striking down Longmont’s ban and Fort Collin’s five-year moratorium on hydraulic fracturing as preempted by state oil and gas law. This was an impressive victory on behalf of COGA and its 90-plus member companies.

  • 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 complex, multi-day rulemaking before the COGCC concerning new flowline regulations governing mapping, registration, removal and integrity management issues.

  • Represents COGA and its member companies with respect to addressing all relevant legislation, 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 Noble Energy and WPX Energy 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.

  • Represented Intercontinental Potash Corp. in all aspects of developing one of the largest potash mines in the country. Representation included guiding the company through every aspect of the multi-year NEPA and the Endangered Species Act permitting process and obtaining all necessary federal, state and local permits.

  • 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.

  • Represented a major home developer in the demolition of the CU Health Sciences Center and the redevelopment of this area for mixed commercial and residential use. Matter involved asbestos and radioactive material abatement, and hazardous and medical waste remediation in over 15 medical buildings.

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, 2015

5280 Top Lawyers, Natural Resources – Oil & Gas, 2015-2019

Best Lawyers in America, 2014-2019

Colorado Super Lawyers, 2012-2013, 2018-2019

Chambers USA, 2010-2019

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