Jonathan D. Tjornehoj, Managing Member

Jon has represented clients in natural resource matters for the past fifteen years. After graduating from the University of Wyoming College of Law, Jon became an associate in the Natural Resources Department at the law firm of Davis Graham & Stubbs LLP. His work there initially focused on litigating environmental and public lands issues relating to natural resource development projects in the Rocky Mountain region. Jon’s practice there later concentrated on oil and natural gas transactions and title examination.

In 2007 Jon started his own law firm under the name Jonathan D. Tjornehoj, LLC, which became Tjornehoj & Hack LLC in 2013. Jon’s new practice initially revolved heavily around providing title curative services—experience that helped inform his later title examination work with a landman’s perspective. Development activities in the Denver-Julesburg Basin continue to form the foundation of Jon’s title practice.

Jon also brings to his practice a broad range of experience, not only in terms of geographic scope but also with respect to project demands. His work has involved everything from simple undeveloped fee properties to complex producing federal units covering thousands of acres.

Prior to attending law school, Jon worked as a field archaeologist for both the United States Forest Service and private contractors. His work involved numerous oil and gas, timber, transportation, and research projects throughout the Rockies.


University of Wyoming, College of Law
Juris Doctorate, with honor, May 2002

Colorado State University
Bachelor of Arts, Anthropology, May 1997

Bar Admissions

Colorado Supreme Court: Oct. 29, 2002
Wyoming Supreme Court: March 21, 2003
Tenth Circuit Court of Appeals: March 15, 2004


Jon Tjornehoj, Complications of Examining Title Within a Pooled Unit, Working Interest Unit, Exploratory Unit or Secondary Recovery Unit, Special Institute on Advanced Mineral Title Examination, Rocky Mountain Mineral Law Foundation (2014).

Jon Tjornehoj, An Overview of Federal and State Mining Claim Records, Special Institute on Mineral Title Examination, Rocky Mountain Mineral Law Foundation (2007).

Scot W. Anderson, Jon Tjornehoj, Peter Hack & Jamie Jost, Law of Federal Oil and Gas Leases, Rocky Mountain Mineral Law Foundation (Ch. 22 update, 2006).

Gregory Danielson and Jon Tjornehoj, Update on the Regulation and Development of Methane From Coal Formations, Special Institute on Development Issues & Conflicts In Modern Oil And Gas Plays, Rocky Mountain Mineral Law Foundation (2004).

Scot W. Anderson and Jon Tjornehoj, Securing and Maintaining Surface Access on Federal Public Lands, Fifty-Fifth Annual Institute on Oil and Gas, Center for American and International Law (2004).

November 18, 2018