|Oregon is the ninth largest state in the United States, covering an area of 98,466 square miles. Located in the Pacific Northwest region of the country, the state is bordered by California to the south, Washington to the north, Idaho to the east and Nevada on the the southeast. The highest point is Mount Hood and the lowest is the Pacific Ocean. It joined the Union in 1859 to become the 33rd state of the United States. The state had an estimated population of about 3.79 million residents in 2008. The valley of Willamette river in its western part has the major concentration of population. Eight of the ten most populous cities in the US are located in Oregon. There are 199 public school districts, 17 community colleges and 7 publicly financed colleges in the state. The major centers of higher education include Oregon State University in Corvallis, University of Oregon in Eugene and Portland State University. Portland is the largest and most populous city in the state. The city is also the 30th largest among all the cities of the USA. Salem is the capital and the third most populous city in Oregon.