The Public Works Department is responsible for the maintenance of 6 parks in Cosmopolis including Mill Creek Park and Makarenko Park. Mill Creek Park holds an annual kids 14 and under fishing derby in Mill Creek Pond as well as the annual Festival in the Park on the second Sunday in September.

Makarenko Park is a 39 acre park that was donated to the City of Cosmopolis by Major D. S. Makarenko . This park consists of over two miles of paved & gravel trails for walking, running, and biking. Aberdeen School District uses this park for its high school cross-country meets in the fall. Makarenko Park also has a program where members of the community can rent a 4’ X 16 ‘garden plot for the summer to grow vegetables. The park also has two soccer fields used by Grays Harbor Youth Soccer for games in both the spring and fall leagues.