It is closely related to the Great Basin and Rocky Mountain bristlecone pines, in the subsection Balfourianae.

Its leaves are needle-like, in bundles of five (or sometimes four, in the southern Sierra) with a semi-persistent basal sheath, and 2–4 cm (1–1+1⁄2 in) long, deep glossy green on the outer face, and white on the inner faces; they persist for 10–15 years.

The cones are 6–11 cm (2+1⁄2–4+1⁄2 in) long, dark purple ripening red-brown, with soft, flexible scales each with a 1-millimeter (1⁄16-inch) central prickle.

In the Sierra Nevada, Foxtail pines are limited to the area around Sequoia and Kings Canyon National Parks.

P. balfouriana is closely related to the bristlecone pines, being classified in the same subsection Balfourianae; it has been hybridised with the Great Basin Bristlecone Pine in cultivation, though no hybrids have ever been found in the wild.