Known as Euclid Avenue for its entire 14-mile (23 km) length, the route begins at its southern terminus at the Chino Valley Freeway (State Route 71) and traverses the communities of Chino, Ontario, and Upland before reaching its northern terminus at the San Bernardino Freeway (Interstate 10).

Through the communities of Ontario, and Upland, the route traverses several designated historic districts, with craftsman homes and civic buildings dating from the late 19th century lining either side of the street.

along major thoroughfares, such as Euclid Avenue, many Upland residents who lived along or near Euclid Avenue did not want a fully functional interchange at the junction between the new freeway and the street as it was anticipated that doing so would increase traffic and noise, thereby undermining the aesthetic qualities of the street and negatively affecting the residents' "quality of life".

Instead, on both sides of the Euclid Avenue overpass there are two wide landscaped areas that provide a visual (and to a lesser extent, acoustic) buffer between the street and the freeway passing below .

Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, based on the alignment that existed at the time, and do not necessarily reflect current mileage.