Mark grew up in New York, attended college in Southwest Ohio and moved to Wyoming in 2000 to work at the Teton Science Schools. After several years of teaching and guiding with TSS, Mark studied environmental and natural resources law earning his degree from Lewis & Clark Law School in 2005. After graduating, Mark moved back to Wyoming joining the Spence Law Firm in Jackson, Wyoming. In 2008, Mark was promoted to serve as the Executive Director of the public interest, not for profit law firm Lawyers and Advocates for Wyoming (L.A.W.), a position he has held ever since. Mark lives south of Jackson with his wife Ryland, daughter Atten (10-named for Sir David Attenborough) and son (Raylan -7), all passionate naturalists of varied abilities.