Gustave Allan Nelson, 92, passed away January 21, 2015 in Boulder, Colorado. He was born May 6, 1922 in Summit, New Jersey to Gustaf Albert and Olga Elizabeth Olson Nelson. He graduated from Summit High School in 1940. Serving as a member of the U.S. Army, he was in the Battle of the Bulge on the first day of the initial assault. He served honorably and received a Purple Heart at the Remagen Bridge. Returning from his Army service, he attended the University of Texas where he graduated in 1947 receiving his Bachelor of Science in Geology. He met and courted Ruth Virginia Kentta, a 2nd Lt. Army veteran, and they were married June 25, 1954 in the Augustana Lutheran Church in Denver, Colorado. G. Allan became a consulting Petroleum Geologist in 1957 and worked in this capacity his entire life. He served as President of the Denver Round Table, Presidents Round Table, Petroleum Pioneers, Remagen Bridge Society, Executive Vice President of Big Brothers, National President of the 99th Division Association and as a member of the Denver Jaycees. He also was a member of the Rocky Mt. Association of Geologists, Wyoming, the Geologic Association, American Association of Petroleum Geologists and the Denver Well Logging Society, becoming an Honorary Lifetime Member. After sharing 53 years of marriage, his beloved wife, Virginia, passed away in 2007. He is survived by his two children, Elizabeth ""Libby"" Nelson Crouch (husband, Scott) and Jon Nelson (wife, Jennifer); five grandchildren, Morgan Crouch, Max Crouch, Henry Crouch, Brooklyn Nelson and Byron Nelson. He was preceded in death by his brother, Robert Nelson. A Memorial service to celebrate his life will be held on Wednesday, January 28, 2015, 9:30am, at Augustana Lutheran Church, 5000 East Alameda Ave., Denver, CO. 80246. A graveside service with Military honors will be held at Fort Logan National Cemetery, 3698 S. Sheridan Blvd, Denver, also on Wednesday, January 28, 2015, at 12 Noon. Please gather in staging area ""A"" at 11:50am.