According to the United States Census Bureau, the CDP has a total area of 4.2 square miles (11 km2), over 99% of it land.

The neighborhood of Spruce Point[4] is located 1.5 miles (2.4 km) northeast of Fields Landing,[4] at an elevation of 49 feet (15 m).

[5] The 2010 United States Census[7] reported that Humboldt Hill had a population of 3,414.

326 households (24.6%) were made up of individuals, and 151 (11.4%) had someone living alone who was 65 years of age or older.

There were 1,269 housing units at an average density of 304.3 per square mile (117.5/km2).

22.9% of all households were made up of individuals, and 10.3% had someone living alone who was 65 years of age or older.

In the state legislature, Humboldt Hill is in the 2nd Senate District, represented by Democrat Mike McGuire,[9] and the 2nd Assembly District, represented by Democrat Chris Rogers.

[10] Federally, Humboldt Hill is in California's 2nd congressional district, represented by Democrat Jared Huffman.