Gil graduated in 1985 with a B.A. in political science from the University of Denver. In 1989 he earned and was awarded a Masters in Landscape Architecture (MLA) from Cornell University.
While at Cornell, he was awarded the William Frederick Dreer Award, allowing him to spend a year in Great Britain studying golf course architecture. While in Britain, he interned with the firm of Hawtree and Son, the oldest continuously practicing golf course architectural firm in the world.
Upon returning to the U.S. he became an Associate, and later a Design Partner, in Tom Doak's Renaissance Golf Design firm. In 1993, he founded Hanse Golf Course Design Inc. based on the principles of creating a small firm that takes a personal interest in the design and construction of each project. The company's courses are simple and elegant in appearance, yet sophisticated in strategy and interest. Hanse takes a hands on approach to golf design and construction spending a large amount on site, often on top of a bulldozer.
His highly acclaimed designs let to his selection to design and oversee construction of the Olympic Course in Rio for the 2016 Olympic Games. In addition to his new course designes, Gil has also established himself as a top restoration specialist.