The Layers of Time are concrete relief tiles affixed to the columns of the shade structures at the Gateway Plazas for the Rio Salado Habitat Restoration Area. The Rio Salado Habitat Restoration Area is a large scale project that has rehabilitated the riparian habitat of the Salt River south of downtown Phoenix, Arizona. The Layers of Time uses five layers of colored, relief tiles to tell the history of the Salt River. The layers are: Geology, Natural History, Native American, Settlement Agriculture, and Contemporary Urban. The relief tiles use impressions of actual objects to create designs that capture the character of different ecological and cultural communities that are part of the local history of the Salt River. The tiles are made from integrally colored, cast concrete that has been stained to bring out details. Each layer is a different color. Each tile is 2′ x 3′. The black and white edges refer to markings used in the river to measure the level of water.
The plans for the Gateway Plazas were created by a design team commissioned by the City of Phoenix. The design team was: Orcutt/Winslow Partnership, architects; Christy Ten Eyck, landscape architect; and Thomas Strich, artist. Thomas went on to produce public art elements for the completed Gateway Plazas.