Mark DeLaquil

Mark DeLaquil

Partner, Baker & Hostetler LLP

Mark DeLaquil has represented FORTUNE 500 companies, states, trade associations, amici curiae groups and public interest groups in regulatory proceedings, complex federal litigation and appellate proceedings. He has been named one of Law360’s “Top 5 Environmental Attorneys Under the Age of 40.”

Environmental Regulatory Proceedings and Litigation

Mr. DeLaquil focuses his practice on complex environmental and regulatory proceedings. He has represented and counseled state and private clients in Clean Air Act administrative proceedings and litigation, including preparing comments on proposed actions and contesting them in the courts of appeals. He has extensive experience in actions concerning climate change, air quality standards, emission standards and state implementation plans.

Appellate Litigation

Mr. DeLaquil has extensive appellate experience, having represented parties and amici curiae in proceedings before the U.S. Supreme Court, the United States Courts of Appeals for the Second, Fourth, Fifth, Seventh and District of Columbia Circuits, and the District of Columbia Court of Appeals.

Complex Dispute Resolution

Mr. DeLaquil has significant experience representing clients in complex federal and international litigation and arbitration. He has counseled clients in international litigation matters arising under the Alien Tort Statute, international environmental and human rights matters. He has also represented clients in litigation arising under the Racketeer Influenced and Corrupt Organizations (RICO) Act, state trade secret laws, copyright infringement and state fraud laws. Additionally, Mr. DeLaquil has represented clients in international commercial arbitrations.

Professional Activities

Mr. DeLaquil has served as faculty on ALI-ABA’s course on Global Warming: Climate Change and the Law. He has been invited to speak on matters concerning the intersection of constitutional and international law by Albany Law School and the Colorado Bar Association’s Bill of Rights Committee. In addition, he has been named one of Law360’s “Top 5 Environmental Attorneys Under the Age of 40.”

Mr. DeLaquil has also authored or co-authored several articles, including “Preemption and Law in the Twenty-First Century,”Chicago Journal of International Law (Winter 2005) and “Foreign Law and Opinion in State Courts,” Albany Law Review (Fall 2006). He also co-authored a chapter in “Presidential Leadership: Rating the Best and Worst in the White House,” The Wall Street Journal (2004) with David B. Rivkin Jr.

  • J.D., Harvard Law School, 2004, cum laude
  • B.A., University of Florida, 2001, magna cum laude


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