Warren has dedicated much of his business career to the development and operation of shopping centers and hotels in Minneapolis-St. Paul. In additional to his business career Warren has been active in non-profit work, including nearly 20 years on the board of VocalEssence and more than 25 years as a trustee of Gustavus Adolphus College, both in Minnesota. He sang in the Plymouth Congregational Church choir and VocalEssence Chorus for a number of years. In 1990 Warren was recognized as Business Person of the Year by the Edina (MN) Chamber of Commerce and, in 1999, as a Volunteer of the Year award recipient by MSP Magazine. That same year he was awarded the Greater Gustavus Award by the college. With his wife, Donna, he has enjoyed a winter home in Tucson for the past 15 years.