According to the United States Census Bureau, the city has a total area of 17.6 square miles (45.7 km), all land, though the path of the Humboldt River fills from time to time.
As of the census of 2000, there were 16,708 people, 6,200 households, and 4,216 families residing in the city. The population density was 1,153.3 people per square mile (445.2/km²). There were 6,948 housing units at an average density of 479.6 per square mile (185.1/km²). The racial makeup of the city was 83.16% White, 0.37% Black, 2.66% Native American, 1.12% Asian, 0.12% Pacific Islander, 9.63% from other races, and 2.94% from two or more races. Hispanic or Latino of any race were 21.12% of the population.
There were 6,200 households out of which 39.2% had children under the age of 18 living with them, 53.5% were married couples living together, 9.1% had a female householder with no husband present, and 32.0% were non-families. 24.5% of all households were made up of individuals and 6.3% had someone living alone who was 65 years of age or older. The average household size was 2.66 and the average family size was 3.24.
In the city, the population was spread out with 30.3% under the age of 18, 9.8% from 18 to 24, 31.2% from 25 to 44, 21.0% from 45 to 64, and 7.6% who were 65 years of age or older. The median age was 32 years. For every 100 females, there were 104.6 males. For every 100 females age 18 and over, there were 105.3 males.
The median income for a household in the city was $48,608, and the median income for a family was $52,754. Males had a median income of $43,397 versus $27,366 for females. The per capita income for the city was $20,101. About 6.1% of families and 8.2% of the population were below the poverty line, including 8.9% of those under age 18 and 8.4% of those age 65 or over.
Elko Nevada neighborhoods include: Argent / Copper, College Park, Elko, Hamilton Stage, North Hollow Estates, Rural Kitridge Canyon, Sagecrest, Sundance, The Pointe at Ruby View, Tree Streets