[5] In addition, a radio control aircraft flying field and a pet memorial garden are within the park's boundaries.

The historic Willowmoor farm and Clise Mansion lie at the western edge of the park, along the Sammamish River.

The brothers renamed the farm Marymoor in honor of Walter's young daughter, Mary Nettleton, who died in a bicycle accident.

[8] In February 2003, King County added a one dollar parking fee to offset budget reductions.

In February 2022, the King County Council passed a "motion of support" for the development of a cricket facility on 20 acres (8.1 ha) of land at Marymoor Park.