Eldorado High School was established in 1973 on an open desert lot just west of the Las Vegas Wash between Washington and Bonanza Roads.

For the first 15 years, Eldorado's zoning covered all of the Sunrise Mountain area north of Charleston Boulevard and east of Pecos Road, which resulted in a total school attendance of more than 2,000.

Its campus is bordered by Washington Avenue, Linn Lane, Harris Avenue and Christy Lane, built with an enclosed building (no windows), an American football stadium with an asphalt running track (one of the first high schools in Las Vegas to have such a track) and a state of the art "sportatorium", used for basketball, volleyball and wrestling as well as assemblies and other school-related activities.

Eldorado Preparatory Academy, the name of the temporary ninth grade campus, closed in spring 2009 when students were rezoned to Sunrise Mountain High School.

Every year, since 1974, Eldorado and Chaparral hold their rivalry game, in which the winner takes possession of a bronzed cleat once owned by the former Los Angeles Rams star Merlin Olsen.