Winterhaven (formerly, Karmack) is a census-designated place (CDP) in Imperial County, California. Winterhaven is located 6.5 miles (10 km) east of Pilot Knob, The population was 394 at the 2010 census, down from 529 at the 2000 census. It is part of the 'El Centro, California Metropolitan Statistical Area'. North of Interstate 8 and bordering Yuma, Arizona, the town is partly located in the Fort Yuma Indian Reservation. The Colorado River is the town's eastern border.
Telephone service is provided by Winterhaven Telephone Company and wired telephones in the area have numbers following the format (760) 572-xxxx. These numbers are assigned to subscribers in Winterhaven, Bard, and Felicity.
The communities of Bard and Felicity, California, appear in the US Geological Survey, National Geographic Names Database and the US Postal Service database and adjoin the community of Winterhaven. The communities of Felicity and Winterhaven share a ZIP code: 92283. Bard does not have postal delivery and post office boxes for the community have a ZIP code of 92222.