Eugene is the second largest city in 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 Oregon

Oregon

Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

 and the seat

County seat

A county seat is an administrative center, or seat of government, for a county or civil parish. The term is primarily used in the United States....

 of Lane County

Lane County, Oregon

-National protected areas:*Oregon Islands National Wildlife Refuge *Siuslaw National Forest *Umpqua National Forest *Willamette National Forest -Government:...

. It is located at the south end of the Willamette Valley

Willamette Valley

The Willamette Valley is the most populated region in the state of Oregon of the United States. Located in the state's northwest, the region is surrounded by tall mountain ranges to the east, west and south and the valley's floor is broad, flat and fertile because of Ice Age conditions...

, at the confluence of the McKenzie

McKenzie River

The McKenzie River is a tributary of the Willamette River in western Oregon in the United States. It drains part of the Cascade Range east of Eugene and flows into the southernmost end of the Willamette Valley. It is named for Donald MacKenzie, a Scottish Canadian fur trader...

 and Willamette

Willamette River

The Willamette River is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is long, lying entirely in northwestern Oregon in the United States...

 rivers, about 50 miles (80.5 km) east of the Oregon Coast

Oregon Coast

The Oregon Coast is a region of the U.S. state of Oregon. It runs generally north-south along the Pacific Ocean, forming the western border of the state; the region is bounded to the east by the Oregon Coast Range. The Oregon Coast stretches approximately from the Columbia River in the north to...

.

As of the 2010 U.S. Census, Eugene has a population of 156,185, and Lane County (co-located with the Eugene-Springfield

Springfield, Oregon

Springfield is a city in Lane County, Oregon, United States. Located in the Southern Willamette Valley, it is within the Eugene-Springfield Metropolitan Statistical Area. Separated from Eugene to the west, mainly by Interstate 5, Springfield is the second-most populous city in the metropolitan area...

 Metropolitan Statistical Area

Table of United States Metropolitan Statistical Areas

thumb|An enlargeable map of the 942 [[Core Based Statistical Area]]s of the [[United States]]. The 367 [[Metropolitan Statistical Area]]s are shown in red....

) (MSA) has a population of 351,715. While Eugene has long been the second largest city in Oregon, it was briefly surpassed by Salem

Salem, Oregon

Salem is the capital of the U.S. state of Oregon, and the county seat of Marion County. It is located in the center of the Willamette Valley alongside the Willamette River, which runs north through the city. The river forms the boundary between Marion and Polk counties, and the city neighborhood...

 between 2005 and 2007.