Scattered to gregarious under conifers in the montaine regions of the state. Also rarely under live oaks in coastal California.
The blue staining of the context of Gastroboletus turbinatus separates this species from other California species of Gastroboletus except Gastroboletus xerocomoides. Macroscopically these two can be differentiated by cap color: Gastroboletus turbinatus has a red to reddish brown cap, whereas Gastroboletus xerocomoides has a brown to olive brown or yellow brown cap. Microscopically Gastroboletus turbinatus lacks the truncate spores of Gastroboletus xerocomoides.