Andrew C. Lillie

Andrew C. Lillie


Email [email protected]​

Phone +1 303 899 7339

Fax +1 303 899 7333

Practice groupLitigation, Arbitration, and Employment

Andy Lillie helps clients solve their trickiest legal problems so they can focus on their business objectives. An accomplished trial lawyer and dispute resolution authority, Andy fervently advocates for his clients as their trusted advisor: he's astute, insightful, attentive, and pragmatic. He has one goal – to lift his client's burden.

Andy is a litigator and regulatory lawyer and leads the firm's Denver Litigation group and co-leads the firm's Energy Disputes group. He handles myriad disputes, often for energy and natural resources businesses with commercial and environmental litigation, regulation, and compliance matters. He counsels clients on dispute prevention and resolution, permitting, cybersecurity, and best business practices.

In the natural resources world, Andy works in the electricity generation, oil and gas, gold and hard-rock mining, wind, solar, and utilities sectors. He handles issues involving toxic torts, land use, air quality, water quality, hazardous waste, and climate change.

Andy advises and defends non-natural resources clients (e.g., real estate developers, governmental agencies, restaurant businesses, sustainability initiatives, land conservation entities, and ski areas) on business and commercial problems and environmental and health issues.

He regularly handles controversies involving public health, local control over resources, eminent domain, public and private land use, real estate, public contracting, resources project development, permitting, and policy formation.

Andy also advises on cybersecurity threat and response, Internet+ (Internet of Things) problem solving, and business integrity, human rights, and sustainability concerns.

Andy serves as a Special Assistant Attorney General for Colorado, and has served as a U.S. Department of Justice Environment and Natural Resources Division intern, and a law clerk for Chief Judge Lewis T. Babcock of the U.S. District Court for the District of Colorado.

"The last time we hired Hogan Lovells to do work for us, I specifically called Andy because of my very positive prior experience in working with him on other matters... I chose to call Andy [because] in working on highly complex and difficult legal issues, I have always found Andy to be thoughtful in his approach, thorough in his analysis, and – most importantly – helpful in his advice."

Mike Jenkins, PacifiCorp Energy

Awards and recognitions


Regulatory Law - United States
Lawyer Monthly Legal Award


Commercial Litigation
The Best Lawyers in America


Environmental Litigation, Rising Stars
Colorado Super Lawyers

Education and admissions


J.D., University of Denver Sturm College of Law, Order of St. Ives, 2002

M.A. Science Journalism, University of Colorado, 2002

B.G.S., University of Michigan College of Literature, Science, and the Arts, 1994

B.S., University of Michigan School of Natural Resources and Environment, with distinction, 1994


Member, American Bar Association

Member, Colorado Bar Association

Member, Downtown Denver Leadership Program

Vice Chair, American Bar Association Energy and Natural Resources Litigation Committee

Member, World Association of Mining Lawyers

Member, Faculty of Federal Advocates CLE Committee

Bar admissions and qualifications



North Dakota

Court admissions

U.S. Court of Appeals, Eighth Circuit

U.S. Court of Appeals, Ninth Circuit

U.S. Court of Appeals, Tenth Circuit

U.S. District Court, District of Colorado

U.S. District Court, Western District of Michigan

Representative experience

Successfully argued BLM lease-prioritization matter in federal court for Peabody Energy, freeing up over US$1bn of coal for extraction.

Won jury trial for AngloGold Ashanti in contract dispute over ownership of gold mine worth approximately US$100m.

Favorably settled toxic-tort lawsuit against Antero Resources in one of the nation's first oil-and-gas hydrofracturing cases.

Favorably settled multimillion-dollar contract-bidding suit against College Assist.

Won wind-project ESA and NEPA lawsuit in California worth approximately US$500m.

Defended Xcel Energy's Comanche III power plant permit in state trial, appellate, and supreme courts.

Defended PacifiCorp's Jim Bridger power plant against alleged Clean Air Act opacity violations.

Favorably settled Colorado State Land Board contract dispute over US$100m water-provision issue.

Favorably settled RCRA citizen-suit against NV Energy's Reid Gardner power plant.

Favorably settled federal contract lawsuit over rights to use midstream oil-and-gas pipeline.

Advises on the Clean Water Act, Clean Air Act, Endangered Species Act, Federal Land Policy and Management Act, Resource Conservation and Recovery Act, and other federal statutes.

Obtained summary judgment in the U.S. District Court for the District of Hawai'i on behalf of tenants of low-income housing project located in Maui, preserving housing until 2051.

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