The Windermere Foundation is celebrating its 25th anniversary by offering a "charity challenge" prize of $25,000 to a nonprofit organization in each of five regions.

Yavapai CASA for Kids is the only nonprofit in Arizona in the challenge. The organization supports children living in foster care.

The winning nonprofit will be determined based on the number of votes received on the Windermere Foundation Facebook page (Facebook.com/WindermereRealEstate) between March 17 and April 4. People may vote daily.