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Meet Our Team

James D. Thorburn

Managing Partner

Jim Thorburn is a nationally recognized and highly experienced litigation and transaction attorney.  Jim Thorburn has been a licensed attorney since 1991. He is one of the founding partners of Thorburn Walker, LLC, primarily located in Greenwood Village, CO with other locations in Longmont, CO and Las Vegas, NV.  


Jim is a highly knowledgeable and experienced commercial litigation attorney, practicing in both state and federal courts.  From 1991 through 2012, Jim’s primary focus was in commercial real estate and construction law.  In 2012, Jim began to practice cannabis tax controversy law, taking on some of the most notable cannabis tax controversy cases in the nation.   This experience has made Thorburn Walker a formidable force in cannabis tax controversy.   

Jim had the honor of arguing, on a writ of mandamus, Feinberg v. Commissioner, 808 F.3d 813 (10th Cir. 2015) in front of now Justice Neil Gorsuch.  Justice Gorsuch’s opinion in Feinberg has been described as a “technical loss but an artful win for the cannabis industry.” 


Jim is on the forefront of the current federal and state issues affecting dispensaries and works hard to achieve successful outcomes for his clients. Jim works with state and national legislators to effect positive legislative change for the cannabis industry. He helps dispensaries, grow facilities, and other businesses navigate through complex federal legal issues including tax court and IRS audits. In addition to Section 280E issues, Jim also provides general business representation, and helps dispensaries comply with the regulations under state cannabis laws.

 Jim has received national recognition as a lead litigating attorney in a majority of the cannabis industry’s high-profile cases.  He speaks on marijuana legal issues across the country and is a featured expert for the National Cannabis Industry Association. He has been featured in CNBC, INC. Magazine, MJ Biz Daily, HBO (Vice News), Denver Post, Law360, Yahoo Finance, National Law Journal, The Cannifornian, and others. 


Jim recently received the coveted 2019 National Law Journal Cannabis Law Trailblazer Award.  The National Law Journal has also designated Jim as a national “Lawyer of Distinction” for 2019. 

In his spare time, Jim is actively involved in motorsports and is the President of the Rocky Mountain Region Porsche Club of America, which is one of the ten largest regions in the United States by membership.   He is also a member of  PCA National Audit Committee.

Jim Thorburn has a B.S. in Business Administration from California State University, Northridge and a Juris Doctor from the University of Denver College of Law.  In his spare time, Jim enjoys serving as the President of the Rocky Mountain Porsche Club of America, racing cars, and flying small airplanes. 


Richard A. Walker

 Attorney at Law

Rich Walker has been a lawyer in the Denver area since 1999. He has also been a CPA in Colorado and California for forty years. Rich is a founding partner of Thorburn Walker LLC, which has offices in the Denver Tech Center and Longmont, Colorado, as well as Las Vegas, Nevada. Rich provides legal counsel emphasizing tax law, cannabis law, and estate planning, and has presented on numerous topics on marijuana business law, tax law, 280E, and Bank Secrecy Act compliance.


Rich was recently awarded the National Law Journal Cannabis Law Trailblazer award for 2019. He is keenly aware of the current federal and state issues affecting dispensaries, and works hard to achieve successful outcomes for his clients. He helps dispensaries, grow facilities, and other businesses navigate through complex legal issues including Tax Court and IRS audits. In addition to 280E issues, Rich also provides general business representation, and helps dispensaries, grow facilities and retail product companies comply with the regulations under the Colorado Medical Marijuana Code.


Rich provides counsel on marijuana legal and tax issues across the country. Rich is admitted to practice in the U.S. District Court of Colorado, the Tenth Circuit Court of Appeals, Federal District Court, District of New Mexico, United States Tax Court and US Supreme Court.


Rich has long understood the ability to focus and succeed in the heat of combat. Rich was a helicopter pilot in the 101st Aviation Division, South Vietnam, During the Vietnam War. Rich still keeps his pilot licenses active and is a commercially rated helicopter and fixed wing pilot. In his free time, Rich loves spending time on his boat and traveling with his grandchildren.

Carolyn M. Schaffer

Attorney at Law

Carolyn Schaffer is an attorney at Thorburn Walker, LLC specializing in marijuana dispensary tax (mainly 280E) and general business matters, as well as commercial real estate, commercial construction, and land use and zoning. Carolyn is also a member of the National Cannabis Industry Association’s State Regulation Committee.

Carolyn has obtained a Juris Doctor from the University of Denver Sturm College of Law, a Master of Science in Legal Administration degree from the University of Denver Sturm College of Law and a Bachelor of Science in Economics degree from the University of Colorado at Colorado Springs.

In her spare time, Carolyn enjoys traveling, spending time with her family, and engaging in fitness activities.

Nathalie M. Caplan

Attorney at Law

Nathalie Caplan is an attorney with Thorburn Walker, LLC who joined the firm in January 2017. Nathalie specializes in cannabis industry tax issues, with a particular emphasis on IRC §280E, as well as general cannabis business matters, constitutional law, and criminal justice issues. Nathalie is a long-time cannabis activist, and is an active member of the National Cannabis Industry Association.


Nathalie obtained a Juris Doctor from the University of Denver Sturm College of Law, a Master of Arts in Conflict Management and Resolution from the University of North Carolina Wilmington, and a Bachelor of Arts in Political Science from the University of North Carolina Wilmington.


While in law school, Nathalie was a member of the University of Denver’s Civil Rights Clinic. Through the clinic Nathalie completed a clemency petition for an individual serving life in prison for a nonviolent drug crime, which was granted by President Obama. Nathalie also graduated law school with the Constitutional Rights and Remedies Certificate from the University of Denver. Nathalie loves working at Thorburn Walker LLC, where she can combine her passion for constitutional law with her advocacy for the cannabis industry.


In her spare time, Nathalie enjoys live music, hiking, traveling, spending time with her fiancé and friends, and bonding with her one-year-old puppy, Evie.

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Dana Tafoya

Office Manager

Joining the firm in 2020, Dana Tafoya's position & role is to represent the firm with an endless vision to grow, manage, and nurture our clients with an emphases on marketing, to help us take us all to new heights.  Dana's passion is helping people & building relationships that last a lifetime.


Dana is a proud native of Colorado.  Her Boys & Doggies keep her busy.  She enjoys concerts, traveling, and riding motorcycles with her husband. 


"The only way to do great work is to love what you do" - Steve Jobs