The Delevan National Wildlife Refuge is one of six refuges in the Sacramento National Wildlife Refuge Complex

Sacramento National Wildlife Refuge Complex

The Sacramento National Wildlife Refuge Complex is part of the United States system of National Wildlife Refuges . It is located in northern California, in the valley of the Sacramento River....

 in the Sacramento Valley

Sacramento Valley

The Sacramento Valley is the portion of the California Central Valley that lies to the north of the San Joaquin-Sacramento Delta in the U.S. state of California. It encompasses all or parts of ten counties.-Geography:...

 of north-central California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. The 5797 acres (23.5 km²) refuge is approximately 80 miles (128.7 km) north of Sacramento

Sacramento, California

Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...

 and consists of over 4500 acres (18.2 km²) of intensively managed wetland

Wetland

A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....

s and 1200 acres (4.9 km²) of uplands.

More than 200,000 duck

Duck

Duck is the common name for a large number of species in the Anatidae family of birds, which also includes swans and geese. The ducks are divided among several subfamilies in the Anatidae family; they do not represent a monophyletic group but a form taxon, since swans and geese are not considered...

s and 100,000 geese

Goose

The word goose is the English name for a group of waterfowl, belonging to the family Anatidae. This family also includes swans, most of which are larger than true geese, and ducks, which are smaller....

 come to the refuge each winter. With 95 percent of the wetlands of the central valley lost over the last 100 years, waterfowl have become increasingly dependent upon the refuges of the Sacramento Valley.

The refuge supports several endangered

Endangered species

An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...

 plants and animals: giant garter snake, wintering peregrine falcon

Peregrine Falcon

The Peregrine Falcon , also known as the Peregrine, and historically as the Duck Hawk in North America, is a widespread bird of prey in the family Falconidae. A large, crow-sized falcon, it has a blue-gray back, barred white underparts, and a black head and "moustache"...

 and bald eagle

Bald Eagle

The Bald Eagle is a bird of prey found in North America. It is the national bird and symbol of the United States of America. This sea eagle has two known sub-species and forms a species pair with the White-tailed Eagle...

, breeding tricolored blackbird

Tricolored Blackbird

The Tricolored or Tricoloured Blackbird, Agelaius tricolor, is a passerine bird of the family Icteridae. Its range is limited to the coastal areas of the Pacific coast of North America, from Northern California in the U.S...

, and a large colony of the endangered palmate-bracted bird's beak. Resident wildlife include grebe

Grebe

A grebe is a member of the Podicipediformes order, a widely distributed order of freshwater diving birds, some of which visit the sea when migrating and in winter...

, heron

Heron

The herons are long-legged freshwater and coastal birds in the family Ardeidae. There are 64 recognised species in this family. Some are called "egrets" or "bitterns" instead of "heron"....

, blackbird

New World blackbird

The New World blackbirds consist of 26 species of icterid birds that share the name blackbird but do not correspond with a formal taxon...

, beaver

Beaver

The beaver is a primarily nocturnal, large, semi-aquatic rodent. Castor includes two extant species, North American Beaver and Eurasian Beaver . Beavers are known for building dams, canals, and lodges . They are the second-largest rodent in the world...

, muskrat

Muskrat

The muskrat , the only species in genus Ondatra, is a medium-sized semi-aquatic rodent native to North America, and introduced in parts of Europe, Asia, and South America. The muskrat is found in wetlands and is a very successful animal over a wide range of climates and habitats...

, black tailed deer and other species typical of upland and wetland habitats.

Approximately 7,000 people hunt on the refuge each year and an estimated 1,000 visitors observe wildlife from a primitive roadside overlook

Overlook

A scenic overlook, or just an overlook, observation point, lookout or viewing point, is a high place where people can gather to view scenery , and to photograph it. Scenic overlooks are typically created alongside mountain roads, often as a simple turnouts where motorists can pull over onto...

along the Maxwell-Colusa Highway.