Aerie is comprised of twenty stone ovoids, nested to create a formal tetrahedral geometry. The sculpture represents a restorative engagement between natural and built systems. The 360 pound ovoidal spheres are carved from limestone, which is commonly used for monuments, construction, and to mitigate acidification of rivers and oceans. Geological events and human interventions that have occurred along the Duwamish River are expressed in the layered strata of a concentric gabion, which serves to frame the sculpture. The sculpture is sited on a landfill of what was once a meander of the Duwamish River and symbolizes an aid to navigation for the evolving stewardship role of the Army Corps of Engineers (USACE). Commissioned for the GSA Art in Architecture Program and sited in front of the USACE Seattle District HQ, on the Duwamish River waterway, the pyramidal stacking connotes stacked projectiles, common features of early fortifications designed by the Corps. A side view of Aerie reveals an elongated tetrahedron and a nesting of ovoidal forms. The ovoid symmetry is consistent with an eagle egg shape and represents a national effort on part of the USACE and others to save and nurture this endangered species. Geological events, historical events, and interventions in the Duwamish River are expressed in the strata of the concentric gabion serving to frame the sculpture. River stone and cobble followed chronologically by shell ‘middens’ and urban rubble fill the gabion in multiple layering. The gabion’s top stratum consists of rubble from the recently demolished Elwha Dam, a restorative effort of historic and national significance. USACE played an important role supporting the National Park Service in its efforts to fully restore the Elwha River and its native salmon populations. The salmon and eagle serve as our “canary in the cage”.