Union Bay Natural Area

Union Bay Natural Area
IUCN category Ib (wilderness area)
Location	Seattle, Washington, United States
Coordinates	47°39′21″N 122°17′38″W / 47.65583°N 122.29389°W / 47.65583; -122.29389Coordinates: 47°39′21″N 122°17′38″W / 47.65583°N 122.29389°W / 47.65583; -122.29389
Area	50 acres (20 ha)
Established	1972
Governing body	University of Washington

The Union Bay Natural Area (UBNA) in Seattle, Washington, also known as Union Bay Marsh, is the restored remainder of the filled former Union Bay and Union Bay Marsh after University Village Shopping Center, the University of Washington (UW) athletic facilities, buildings, and main parking area (E1). It is located at the east end of the main UW campus, south of NE 45th Street and west of Laurelhurst. Ravenna Creek is connected to University Slough (Drainage Canal), thence to Union Bay, and Lake Washington. Drainage Canal is one of three or four areas of open water connected with Lake Washington around Union Bay Marsh. The canal extends from NE 45th Street, between the driving range and IMA Sports Field 1, south to the bay, ending southeast of the Husky Ballpark baseball grandstand (northeast of the IMA Building). The Drainage Canal that carries Ravenna Creek past UBNA to Union Bay is locally sometimes called University Slough, though that is something of a misnomer in that "slough" is both used in the eastern and southeastern U.S. meaning, rather than the western U.S. meaning, and it is no longer a natural watercourse in that it is a canal that replaced bay and marsh, both now filled.

The little grasslands, modest ponds, and lake shoreline of the UBNA is a sanctuary for birds (most dramatically crested cormorants, great blue herons, and eagles); turtles and frogs may be seen. The UBNA is notable for diverse habitats including a good-sized lake, small permanent ponds, seasonal ponds, woods, sample prairie, and marshland. The interfaces among these make the area particularly attractive for birdwatching, with more than 150 species of birds sighted. The canal or slough was part of a restoration of the wetlands called Union Bay Marsh that had been drained by the opening of the Montlake Cut of the Lake Washington Ship Canal (1916) and much of Union Bay filled by the Montlake Dump, (home of J. P. Patches, resident 1958-1981). Formerly the Montlake Landfill, University Dump, or Ravenna Landfill, it was used by the City of Seattle for residential and industrial solid waste from 1911 to 1966. It was fully closed five years later and overlaid with two feet of clean soil. Most of the land has been built upon by University Village (1956), UW athletic fields, buildings, and main parking lot E; the remainder comprises the UBNA, colloquially called "the fill".