Adrian 'Andy' Onderdonk, aged 75 of Hampstead, NH and Sanford, FL, passed away peacefully on Thursday May 27 ^th .  He was a graduate of Winter Park High School and the Connecticut School of Electronics.  He joined the Navy and proudly served his country in Vietnam, earning a Purple Heart.  He went on to have a career as a Field Service Engineer, displaying a wonderful knack for solving problems.  He married Susan Marrs in 1975 and spent 38 joyful years together until her passing in 2013.  He volunteered hundreds of hours with the New Hampshire Multiple Sclerosis Society and was a member of the Board of Directors.  He was also a Hunter Education Instructor for the New Hampshire Fish & Game Department for over 35 years, serving as the Chief Instructor for the last decade.  He had been a member of the Merrimack Valley HOG Chapter and was editor of their newsletter for several years.  He was an amazing husband and father who coached softball teams, helped with Girl Scouts, went to track meets and was always there for his family.  He loved to sit and tell stories and regale his friends with his travels.  He was the example of altruism in its best form.  He would always help those around him without a second thought to himself.  He is survived by his brother, Peter Onderdonk; his daughter Jillian Tremblay and her spouse Jean-Francois Tremblay and so many very loved friends.  Due to the ongoing pandemic, services will be held in small private gatherings.  We ask that people please celebrate him on his Facebook page and in their hearts.