The landfill opened in 1963 and is the county's only active waste facility, serving an estimated 1.4 million people in King County—excluding the cities of Seattle and Milton.

[8] The facility was initially expected to handle the county's garbage needs for up to 40–50 years, but the addition of a contract with the City of Seattle caused capacity concerns by the late 1960s.

[15] Cedar Hills was designated as a high-risk hazardous site by the Washington State Department of Ecology in 1992 due to the presence of arsenic, lead, and benzene in groundwater.

[2] The landfill is also home to a population of bald eagles, ravens, crows, and seagulls who pick up garbage and drop pieces in surrounding neighborhoods.

[17] Beginning in January 2025, Cedar Hills was closed on weekends as part of a pilot program to reduce operating costs that are not fully recouped from fees on commercial garbage haulers.