Peter was the fourth child born to parents Peter and Mary (Isley) Gesellchen, on February 28, 1954, in Linton, ND.  Pete grew up and attended grade school and high school in Hazelton-Moffit Schools, graduating in 1972.  While in high school he played basketball with the Hazelton- Moffit Tigers.  He attended North Dakota State University in Fargo, and graduated in 1976 with a Bachelor's degree in Architecture.  Later, when he was working in Arnold, Maryland, he studied and received a bachelor's degree in engineering.

After college, Pete worked for Swenson and Hagen Engineering, in Bismarck.  In the late 1970's he moved to the east coast and worked for various engineering firms in Washington DC, Annapolis and Baltimore, Maryland for 35 years.  In 2007 he returned to North Dakota and worked in Fargo, Grand Forks and Bismarck in various engineering capacities. He was working for the State of North Dakota as an engineer when he retired.

Throughout his life, Pete enjoyed getting together for holidays with his family. He had great knowledge of his family's history and had done research at the National Archives in Washington DC going back several generations.  He enjoyed doing things with his brothers and sister.  Pete enjoyed the old car hobby.  He and his brother Rodney went to many car shows in ND, and he enjoyed going to "Back to the Fifties" in St. Paul, MN, as well as numerous car shows in MN with his brother Cliff.   When he worked on the east coast, he went to the big cars shows such as those in Hershey, PA.  Pete enjoyed going to the NDSU football games with his sister Mary and brother-in-law Kirby, and nephew Alex.

At the time of his death, Peter was on the Hazelton City Commission. He enjoyed researching and writing historical articles for the Hazelton newsletter.

Pete is survived by his brother, Cliff (Jo Ann) Gesellchen, and his sister Mary Nielsen. He is also survived by nephews and nieces, John Carlson, Andrea (Joel) Ostapowich, and their son Isaac; Michael (Jessica) Gesellchen and their children, Evan and Cora;  Angie (Josh) Clarke; Andrew Nielsen; Adam (Taylor) Nielsen and their children, Knox, Kennedy, and Kamryn; and Alex Nielsen.

Peter was proceeded in death by his parents, Peter and Mary Gesellchen, sister Marlene Carlson, brother Rodney Gesellchen and brother-in-law Kirby Nielsen.