Between downtown Los Angeles (its western terminus at its interchange with Interstates 5 and 10) it had an existence separate from U.S. Routes 70 and 99, lying to its south. US 60 passed through Pomona and Riverside, meeting US 70 and US 99 near Beaumont, east of which it coincided with US 70 and US 99 as far to the east as Indio. East of Indio, US 99 separated from US 60 and US 70, both continuing through the Mojave Desert to the Arizona state line at the Colorado River near Blythe almost entirely as a two-lane highway.