San Gabriel River Freeway

Interstate 605
San Gabriel River Freeway
I-605 highlighted in red
Route information
Defined by
Maintained by Caltrans
Length:	27.40 mi (44.10 km)
History:	1940s as a state highway, 1964 as a number
Major junctions
South end:	SR 22 / I-405 in Seal Beach
	SR 91 in Cerritos I-105 in Norwalk I-5 in Santa Fe Springs SR 72 in Whittier SR 60 in Avocado Heights I-10 in Baldwin Park
North end:	I-210 / Huntington Dr. in Irwindale
Location
Counties:	Los Angeles
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future State highways in California Interstate U.S. State Pre-1964 History Unconstructed Deleted Freeway Scenic ← I-580 I-680 →

Interstate 605 (abbreviated I-605, officially known as the San Gabriel River Freeway) is a major north–south Interstate Highway in the Greater Los Angeles Area of Southern California. It is about 27 miles (43 km) in length, and runs from Seal Beach to Irwindale, closely paralleling the San Gabriel River for most of its alignment. The San Gabriel River Freeway is one of the few Southern California freeways not named after a city along its route.

This route is part of the California Freeway and Expressway System.

The California Streets and Highways Code defines Route 605 as "(a) Route 1 near Seal Beach to Route 405. (b) Route 405 to Route 210 near Duarte." However, the portion in subsection A has yet to be constructed.

The southern terminus of I-605 is at the San Diego (I-405) and Garden Grove (State Route 22) Freeways in Seal Beach. From there, it runs roughly north through the Gateway Cities of the Los Angeles Basin. It then shifts north-northeast, crossing the Whittier Narrows and across the San Gabriel Valley. I-605 then ends at its junction with the Foothill Freeway, (I-210) in Duarte, a small city located at the foothills of the San Gabriel Mountains.