Robert Morris Earthwork, Land art installation in SeaTac, United States.

Robert Morris Earthwork is a land art installation featuring concentric terraced circles carved into a reclaimed gravel pit. The design creates layered levels that descend gradually across the site.

The King County Arts Commission selected this location from numerous gravel pits in 1979 to create the first permanent land reclamation artwork in the United States. This choice marked a new approach to transforming industrial sites through art.

Robert Morris made the earthwork for a 1979 King County symposium, "Earthworks: Land Reclamation as Sculpture", which also led to the Mill Creek Canyon Earthworks. The county's former public art director calls the two the major earthworks in King County, and 4Culture rates this one as of international importance.

The site is located south of Seattle on a reclaimed industrial property that visitors can walk through at their own pace. Moving down through the terraced levels helps you understand the full scope of the design.

The earthwork came out of a King County symposium titled Earthworks: Land Reclamation as Sculpture, which also led to the Mill Creek Canyon Earthworks; a former public art director calls the two the major earthworks in King County. The site was listed on the National Register of Historic Places in 2021.