The Gates Family Foundation is one of the largest philanthropic organizations in Colorado, based in Denver.
Background
Founded in 1946, the Foundation currently has net assets of approximately $500 million. In 2007, the Foundation paid roughly $20 million in grants, all of which went to Colorado recipients.
The source of the original endowment is the Gates Rubber Company of Denver, Colorado.
The Foundation is well known in Denver, for example including the Gates Planetarium at the Denver Museum of Nature and Science.
References
Gates Family Foundation Wikipedia(Text) CC BY-SA