About Mark R
Mark R Petersen earned his J.D. from the University of Idaho College of Law in 2001 after completing a B.S. in Environmental Science at Brigham Young University in 1997. Those formative years combined technical training in the natural sciences with formal legal study. The pairing helped shape an early interest in matters that intersect law and natural resources.
Petersen began his post-law-school career in the Idaho legal community in the early 2000s. In 2004 he served as an extern with the Idaho Attorney General’s Department of Water Resources. That same year he worked as a staff lawyer in the Sixth Judicial District for Judge Peter McDermott. He joined private practice a year later as an associate at M. Brent Morgan Chartered, where he handled a range of civil matters.
In 2009 Petersen started Snake River Law PLLC and has been the owner since. Over time he has moved from staff roles in the public sector into sustained private practice. His path reflects steady progression: public service, associate work in a small firm, and then founding his own practice.
He is admitted to practice in Idaho and before the Ninth Circuit. Petersen has held membership in the Idaho State Bar since 2004 and remains an active member. He also serves on the Sixth District Citizens Law Academy committee, a role he has held since 2004, where he participates in community-oriented legal education and outreach efforts.
Colleagues describe Petersen as methodical in the courtroom and thorough in preparation. He has experience managing cases in both trial and appellate settings, and his background includes work under a district judge and in a state regulatory office. Those roles reinforced courtroom procedure, case administration and regulatory experience.
Petersen’s practice balances litigation and client counseling. He has handled matters in state trial courts and in federal filings that proceed to the Ninth Circuit. He currently works from Snake River Law PLLC and focuses on litigation in Idaho state courts and before the Ninth Circuit.
