Person Photo
Person Photo

Andrew Lillie


555 17th Street, Suite 3200, Denver, CO 80202

An experienced litigator and passionate advocate, Andy is a problem solver who provides strategic, business-focused counsel to clients facing complex disputes and regulatory challenges.

Andy’s goal is to make his clients’ lives easier so that they can focus on their business goals, rather than legal issues. Andy helps alleviate the economic, intellectual, and emotional stress and disruption that legal matters create.

Andy’s wide-ranging energy and natural resources practice includes handling commercial disputes, administrative enforcement actions, and federal and state environmental regulatory predicaments for clients in the oil and gas, gold and hard-rock mining, renewable energy (wind, solar, hydropower, battery storage), and electric power generation sectors. He also counsels energy industry clients on regulatory compliance, cybersecurity threats, supply chain integrity, and Environmental, Social, and Governance (ESG) planning and compliance issues.

Andy also helps clients proactively manage business and commercial problems, creating solutions to resolve issues up front and to avoid litigation when possible. He handles a diverse variety of business disputes for clients in the food and beverage, heavy-industry, real estate, and agriculture industries.

show more


Energy and Resources Litigation
  • Citizen suits
  • Clean Air Act (CAA)
  • Clean Water Act (CWA)
  • Endangered Species Act (ESA)
  • Federal Land Policy and Management Act (FLPMA)
  • Foreign Corrupt Practices Act and Anti-Corruption (FCPA)
  • National Environmental Policy Act (NEPA) 
  • Resource Conservation and Recovery Act (RCRA)
  • State and local statutes and regulations
  • Toxic torts
Regulatory Compliance 
  • Air quality
  • Climate change
  • Environmental health and safety
  • Environmental Social and Governance (ESG)
  • Hazardous waste
  • Project permitting and infrastructure 
  • Water quality
Commercial Disputes
  • Alternative Dispute Resolution
  • Commercial contracts and torts
  • FOIA/sunshine acts
  • Food and restaurant issues
  • Government contracts
  • Local control over resources
  • Public health issues
Land Use
  • Conservation
  • Eminent domain
  • Leasing
  • Private land use
  • Public lands
  • Sustainability
  • Energy and infrastructure cybersecurity threats
  • Energy and infrastructure supply chain integrity
  • Internet+ (Internet of Things)



Speaking Engagements


Bar Admissions

Court Admissions


  • The Best Lawyers in America©, Commercial Litigation, 2021-2023; Administrative/Regulatory Law; Natural Resources Law, 2023
  • Lawyer Monthly Legal Award, Regulatory Law—United States, 2020

Professional and Civic Affiliations

  • American Bar Association, Section of Environment, Energy, and Resources, Member
    • Energy and Natural Resources Litigation Committee, Vice Chair, 2017–present
  • Faculty of Federal Advocates, CLE Committee, 2019–present
  • Colorado Governor’s Board of Ethics, Chair, 2021–present
  • National Institute for Trial Advocacy, Instructor
  • Foundation for Natural Resources and Energy Law, Member
    • Natural Resources and Energy Litigation Program Committee
  • Colorado Bar Association, Member
  • Downtown Denver Leadership Program, Member
  • World Association of Mining Lawyers, Member
  • Guest lecturer on natural resources topics at Colorado School of Mines, North Dakota State University, and University of Denver
Widget Image

Unless you are a current client of Holland & Hart LLP, please do not send any confidential information by email. If you are not a current client and send an email to an individual at Holland & Hart LLP, you acknowledge that we have no obligation to maintain the confidentiality of any information you submit to us, unless we have already agreed to represent you or we later agree to do so. Thus, we may represent a party adverse to you, even if the information you submit to us could be used against you in a matter, and even if you submitted it in a good faith effort to retain us.