 During and after his business career, Dendahl served on the boards of directors of numerous charitable organizations, including United Way, Sangre de Cristo Girl Scout Council, New Mexico Association of Commerce and Industry, the Santa Fe Opera, Santa Fe Preparatory School, School of American Research (now School for Advanced Research), Mountain States Legal Foundation (MSLF), and St. John's College.Dendahl was chairman of the board for St. John's College for two years.Dendahl served as New Mexico's Secretary of Economic Developmant and Tourisim from 1988 to 1990 a position he was appointed to by Governor Garrey Carruthers.