The region is underlain by the Coast Plutonic Complex, consist- ing of pre- to post-kinematic quartz diorite to granodiorite batho- liths intruded into Paleozoic to Mesozoic metasedimentary and meta- volcanic rocks. Younger supracrustal assemblages overlying deformed include the (?)Cretaceous Gambier Group and Tertiary Bella Bella Formation volcanic rocks.

The Eucott hot springs contains a very low amount of dissolved solids (145 milligrams per litre) which has a calcium sulphate, calcium bicarbonate composition. Water temperature at the surface is in excess of 60 degrees celsius. The rocks underlying the area comprise a foliated quartz diorite into which a post kinematic granodioritic stock has been intruded.