It occurs most commonly in western North America in association with two-needle and three-needle pine hosts.

Rhizopogon occidentalis was first described by Sanford Myron Zeller and Carroll William Dodge in 1918 from collections made in Moscow, Idaho; Klickitat Co. and Bingen, Washington; Between Hood River and Mosier, Oregon; and Pacific Grove, California.

[2] They have white hyphae 2–5 mm in width and 5-25 um in length with simple dichotomous branching and thick rhizomorphs.

[9] They lack clamp connections and deposits of what is thought to be calcium oxalate found on the mantles of some other members of their genus.

[11][12][13] Early establishment after fire may also be aided by its spores greater heat resistance relative to some cooccurring ectomycorrhizal species.