Fumarole Butte is a basaltic flow erupted during Pleistocene time. It is a basaltic example of the bimodal basalt-rhyolite volcanism that accompanied basin-range faulting during Miocene to present time. The butte is located about 20 miles southeast of Spor Mountain and can be accessed by road along the east side, from the paved highway connecting Spor Mountain to route 50. A detailed geologic map of the butte and surrounding Lake Bonneville deposits was made by Galyardt and Rush (1981).

SLIDE 41 is an aerial view of Fumarole Butte looking northeast; the snow-capped mountains on the skyline are the Oquirrh Range.