Trinity River National Wildlife Refuge was established on January 4, 1994 with an initial purchase of 4400 acres (17.8 km²). Since that time, the refuge has acquired additional acreage which now totals 25000 acres (101.2 km²). The primary purpose of establishing this refuge is to protect a portion of the bottomland hardwood

Hardwood

Hardwood is wood from angiosperm trees . It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.Hardwood contrasts with softwood...

 forest ecosystem along the Trinity River

Trinity River (Texas)

The Trinity River is a long river that flows entirely within the U.S. state of Texas. It rises in extreme north Texas, a few miles south of the Red River. The headwaters are separated by the high bluffs on the south side of the Red River....

 located in southeastern Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

. The refuge, which is a remnant of what was once a much larger natural area is a broad flat floodplain

Floodplain

A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...

 made up of numerous slough

Slough

Slough is a borough and unitary authority within the ceremonial county of Royal Berkshire, England. The town straddles the A4 Bath Road and the Great Western Main Line, west of central London...

s, oxbow lake

Oxbow lake

An oxbow lake is a U-shaped body of water formed when a wide meander from the main stem of a river is cut off to create a lake. This landform is called an oxbow lake for the distinctive curved shape, named after part of a yoke for oxen. In Australia, an oxbow lake is called a billabong, derived...

s, artesian wells, and tributaries.