The Arc Of Arapahoe & Douglas

People First, Democracy, Visionary Leadership, Community Participation, Diversity and Integrity and Excellence. The Arc of Arapahoe & Douglas Counties is a private, nonprofit organization committed to delivering advocacy, information and maintenance to people with developmental disabilities and their families. The Arc of Arapahoe & Douglas opened it's doors in 1955, and through the years, the organization has continually provided services that promote the general welfare of people with developmental disabilities including.