John Thomas Colgan, 95, Hermosa, died peacefully Sunday, May 10, 2015, at his home on Lower Spring Creek Road surrounded by his wife and other family members. John, the oldest of nine children, was born on December 28, 1919, in Rapid City, SD, to Thomas and Lillie (Hart) Colgan. He was raised in the Spring Creek area and attended the local country school. He graduated from Rapid City High School in 1937, and then enrolled in the electrical engineering program at the SD School of Mines in Rapid City. Following his graduation from the School of Mines in 1942, he accepted a position with General Electric (GE) in Fort Wayne, Indiana. Later assignments with GE took him to Lynn, Massachusetts, Schenectady, New York, and back to Fort Wayne. His initial years at GE centered on the production and testing of turbines and generators which powered Liberty ships during WWII. On June 10, 1942 he married Laura E. Watson from Rapid City and to this union six children were born: Thomas (& Cathy), Hermosa, SD; James (& Cely), Phoenix, AZ; Juliet (& Darrell) Svalstad, Pueblo, CO; Daniel (& Geralyn (“Jay”)), Hermosa, SD; Elizabeth (& Roger) Dikoff, Hermosa, SD; and Robert, Hermosa, SD. In 1948, John left GE and returned to Rapid City to work for Montana Dakota Utilities. In 1950, he and another School of Mines graduate formed a partnership and started a consulting engineering company. It was during this time that he performed surveys for, and designed, many of the Rural Electrical Association (REA) power lines throughout the Black Hills area. He was a registered professional engineer and land surveyor for much of his life. In 1962, John retired from the engineering profession and returned to his roots in agriculture. Since that time, he has ranched in and around the Hermosa area while residing on Lower Spring Creek Road, near the homestead where he was raised. John enjoyed the challenges associated with improving agricultural land, turning it into something more useful and valuable for the next generation. His efforts included planting trees, building stock dams, rebuilding fences, and upgrading water sources and roads. He was a founding member of the group of ranchers that developed the rural Hermosa Water Users Association. He loved the country and was a good steward of the land. John was a longtime member of the Pennington County Planning and Zoning Commission, as well as a member of the South Dakota Stockgrowers Association, South Dakota Farmers Union, Canyon Lake Senior Citizens Group, and Our Lady of Perpetual Help Catholic Church. He was a generous supporter of the Rapid City Catholic School System and the SD School of Mines. John’s first wife Laura passed away on November 22, 1983. On April 28, 1984 he married Betty Anne Bahr-Lazor; his steady companion until she passed away on April 20, 2010. On February 3, 2011, he married Helen O’Bryan-Lopez who was his compassionate companion until his death. He is survived by his wife, Helen, all six of his children, 18 grandchildren, 18 great-grandchildren, as well as five siblings; Robert, Thousand Oaks, CA; Jean Shea, Granada Hills, CA; Joyce Paulsen, Klamath Falls, OR; Maureen (& Carl) Ensor, Rapid City, SD; Donald (& Gilda), Riverside, CA; 9 step-children and numerous nieces and nephews. He was preceded in death by his brothers, Patrick and Daniel, and sister Mary Jane Carrieres and step-daughter Nancy Lazor.