Salt Lake County is part of the Salt Lake City Metropolitan Statistical Area as well as the Salt Lake City–Ogden–Clearfield Combined Statistical Area.
As of the census of 2000, there were 898,387 people, 295,141 households, and 213,977 families residing in the county. The population density was 1,218 people per square mile (470/km²). There were 310,988 housing units at an average density of 422 per square mile (163/km²). The racial makeup of the county was 86.34% White, 1.06% Black or African American, 0.88% Native American, 2.56% Asian, 1.23% Pacific Islander, 5.36% from other races, and 2.57% from two or more races. 11.89% of the population were Hispanic or Latino of any race. The top 5 Ethnic Groups in Salt Lake County are:
By 2007 Non-Hispanic whites were 76.5% of Salt Lake County's population and Latinos now were 15.7% of the population. African-Americans were now 1.7% of the population. Asians were 3% of the population, while Pacific Islanders were 1.3%. Native Americans were still 1% of the population. The Census' 2005 American Community Survey indicated that 11.4% of Salt Lake County's population living in households (as opposed to group arrangements such as college dormitories) spoke Spanish at home.
In 2000 there were 295,141 households out of which 40.10% had children under the age of 18 living with them, 57.80% were married couples living together, 10.40% had a female householder with no husband present, and 27.50% were non-families. 20.80% of all households were made up of individuals and 6.20% had someone living alone who was 65 years of age or older. The average household size was 3.00 and the average family size was 3.53.
In the county, the population was spread out with 30.50% under the age of 18, 12.90% from 18 to 24, 30.60% from 25 to 44, 18.00% from 45 to 64, and 8.10% who were 65 years of age or older. The median age was 29 years. For every 100 females there were 101.70 males. For every 100 females age 18 and over, there were 99.70 males.
The median income for a household in the county was $48,373, and the median income for a family was $54,470. Males had a median income of $36,953 versus $26,105 for females. The per capita income for the county was $20,190. About 5.70% of families and 8.00% of the population were below the poverty line, including 9.00% of those under age 18 and 5.50% of those age 65 or over.
By 2008 the county population had risen 13.8%to 1,022,651. This was a rise below the rate for the state overall; however, Utah was the fastest growing state in 2008 according to the U.S. Census Bureau.
The county is traversed by three Interstate Highways and one U.S. Highway, as well as an additional freeway and one major expressway. US-89 enters from Davis County to the north and traverses the county arrow-straight until merging with I-15 in north Draper. It is known as State Street along most of the route and is the primary surface road in the valley. I-15 and I-80 intersect just west of Downtown Salt Lake City, merging for approximately 3 miles (5 km) north-to-south. I-80 continues west past the Salt Lake City International Airport and east through Parley's Canyon and into the Wasatch Range. I-15 traverses the valley north-to-south, providing access to the entire urban corridor. The freeway is 10-12 lanes wide after a major expansion project from 1998 to 2001 undertaken in preparation for the 2002 Winter Olympics. I-215 directly serves many of the suburbs of Salt Lake City in the western, central, and eastern portions of the valley in a 270° loop. It enters from Davis County, intersecting I-80 just east of the airport and I-15 in Murray, and ending after intersecting with I-80 at the mouth of Parley's Canyon. From the southern I-80/I-15 split on the border of Salt Lake City and South Salt Lake, SR-201 heads west as a freeway along the border with West Valley City, eventually becoming an expressway and ending at I-80 near the Tooele County border. Bangerter Highway (SR-154) is an expressway that traverses the entire western end of the valley from the airport, ending at I-15 in southern Draper. SR-68, or Redwood Road, is the only surface street that traverses the entire valley from north-to-south.
A light rail system, known as TRAX, is operated by the Utah Transit Authority (UTA) and runs from the Salt Lake Central Station in downtown Salt Lake City south to Sandy, with another line east to the University of Utah; the system currently has 28 stops. Extensions to the airport, West Valley City, South Jordan and Draper have been funded and approved, with completion of all four expected by 2014. A commuter rail line, FrontRunner, began operation in April 2008 between the Salt Lake Central Station in downtown Salt lake City and Pleasant View, a northern suburb of Ogden. An extension south to Provo has been approved and is expected to be complete by 2012. UTA also operates bus routes to nearly every location in the valley and routes to the ski resorts in winter. The Legacy Parkway section of the Legacy Highway project is eventually planned to intersect with I-215 near the northern border of the county. The Mountain View Corridor is a freeway planned to be constructed down the far west side of the valley. A historic streetcar is also being considered along 2100 South from the TRAX station to the historic business district in the Sugar House neighborhood.