[2] Herlong is located at the extreme eastern edge of the Sierra Nevada Mountain Range in the southeastern region of Honey Lake Valley, 8 miles (13 km) north of Doyle,[4] at an elevation of 4,114 feet (1,254 m).

Herlong was developed in 1942 after the attack on Pearl Harbor during World War II, to house civilian workers to support the Sierra Army Depot, one of several ammunition storage facilities located inland in order to be safe from Japanese attack.

The community was named after Captain Henry W. Herlong, the first United States Army ordnance officer to die in World War II.

[4] The postal stamps, money orders and equipment bore the spelling "Hurlong", which lasted for about five days; the error was discovered and corrected.

According to the United States Census Bureau, the CDP has a total area of 1.6 square miles (4.1 km2), all land.

This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 °F.

There were 139 housing units at an average density of 85.4 per square mile (33.0/km2), of which 0 (0%) were owner-occupied, and 116 (100%) were occupied by renters.

[9] Federally, Herlong is in California's 1st congressional district, represented by Republican Doug LaMalfa.