Dr. Hallman did his undergraduate work at the University of Wyoming. He received his Doctor of Veterinary Medicine from Kansas State University in 1985. Dr. Hallman opened Star Valley Veterinary Clinic in May of 1985.
Dr. Hallman has been a consulting veterinarian for the Humane Society of Central Arizona, Payson Pro Rodeo, Payson Zoo, Payson Natural Resources Committee, and the Arizona Game and Fish Department.
Sled dog medicine is a passion of Dr. Hallman's and he has been vetting sled dog races in Alaska and Canada since 1994, including the Yukon Quest 1000 mile raceand the Copper Basin 300. He served as the Yukon Quest Head Veterinarian in 1996, 1997 and again in 2010.
He has been on the board of International Veterinary Sled Dog Medical Association since 2015.
Dr. Hallman's personal interests include hiking, travel, photography and volunteer work.