Winnemucca Lake, just east of Pyramid Lake in the northwestern portion of the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Nevada

Nevada

Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...

 is on the dividing line between Washoe County

Washoe County, Nevada

Washoe County is a county located in the U.S. state of Nevada. The population was 421,407 at the 2010 census. Its county seat is Reno. Washoe County includes the Reno-Sparks metropolitan area.-History:...

 and Pershing County

Pershing County, Nevada

Pershing County is a county located in the U.S. state of Nevada. As of the 2000 census, the population was 6,693. Its county seat is Lovelock. The county was named after army general John J. Pershing . It was formed from Humboldt County in 1919, and the last county to be established in...

 counties.

Geography

The lake was formerly a shallow tule

Tule

Schoenoplectus acutus , called tule , common tule, hardstem tule, tule rush, hardstem bulrush, or viscid bulrush, is a giant species of sedge in the plant family Cyperaceae, native to freshwater marshes all over North America...

-filled lake and an important stop for migrating

Bird migration

Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...

 waterfowl

Waterfowl

Waterfowl are certain wildfowl of the order Anseriformes, especially members of the family Anatidae, which includes ducks, geese, and swans....

. After the Derby Dam

Derby Dam

Derby Dam is a diversion dam on the Truckee River, located between Reno and Fernley in Storey and Washoe counties in the U.S. state of Nevada. It diverts water that would otherwise feed Pyramid Lake into the Carson River watershed for irrigation use. It is operated by the Truckee-Carson...

 was built on the Truckee River

Truckee River

The Truckee River is a stream in the U.S. states of California and Nevada. The river is about long. Its endorheic drainage basin is about , of which about are in Nevada. The Truckee is the sole outlet of Lake Tahoe and drains part of the high Sierra Nevada, emptying into Pyramid Lake in the Great...

 in 1903 (the first project of the Reclamation Act), and State Route 447 (which blocked the slough

River delta

A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...

 connecting it to Pyramid Lake) was built, Winnemucca Lake dried out and has remained dry since the late 1930s.