How can I pay my fines? Admin April 15, 2019 18:02 Updated Follow You may pay your fines online, at any library self-check kiosk, or by mailing a check to Douglas County Libraries at 100 S. Wilcox Street, Castle Rock, CO 80104. Learn more about Fines, Fees and Borrowing. Related articles How do I log in for the first time? What is my library card number and PIN? I think I lost a library book. What should I do? I lost my library card. What should I do? How can I renew my books? Comments 0 comments Article is closed for comments.