The Wells Gray region of east-central British Columbia is a volcanic field made up of numerous, small, basaltic volcanoes. Individual volcanoes have been active for at least the last 3 million years during which time the region was covered by thick glacial ice at least twice, prior to the well known Fraser Glaciation (also known as the 'Wisconsin Glaciation'). Volcanic eruptions underneath and through the thick blankets of glacial ice produced numerous unique glacial volcanoes and deposits, including one explosive, subaqueous volcano, five tuyas, at least one subglacial mound, and numerous, thick, valley-filling deposits of volcanic rocks. Between the periods of glaciation, the volcanoes continued to erupt and filled river valleys with many layers of basaltic lava flows. The valley-filling flows, now incised by rivers, have created a unique landscape of steep, narrow valleys and numerous waterfalls. A particularly beautiful waterfall is the 142 m (465 ft.) high, free-falling Helmcken Falls. Its beauty and that of the surrounding area prompted the provincial government to set the area aside as a park in 1939.

A single road enters the park, but from it, a number of the park's volcanic features can be viewed. Short hikes lead to several spectacular volcanic features. The road terminates at the southern end of Clearwater Lake, where a short hike up the Kostal Lake trail leads to the Dragon's tongue lava flow. The flow, which is now punctuated by tree moulds visible from the trail, travelled 15 km from the vent. It forms a 3 m high dam across the southern end of Clearwater Lake, which maintains the existing lake level. This flow is just one of the examples of volcanic activity that have occurred in the region since the last ice age. This activity involved small fire-fountaining eruptions that produced cinder cones and lava flows. Other cones in the area include Kostal cone (at a few hundred years old, it is most likely the youngest in the region), Flourmill cone, and Spanish cones. Some lava flows at Wells Gray Park are unique in that they contain small, angular to rounded fragments of rock (called 'nodules') and crystals that come from the mantle below the Earth's crust. These green nodules are called 'peridotites' because they are composed predominantly of the mineral olivine (the gem form of which is known as 'peridot'). These lavas also contain large crystals of olivine, plagioclase, and pyroxene that crystallized deep within the Earth's crust and mantle. The lavas and the nodules they contain are similar to those erupted in the Volcano Mountain area of the Yukon Territory. The nodules help scientists determine what the mantle below the volcano is like.

A viewing platform on Green Mountain in the southern part of the park affords views of a number of the park's tuyas including McLeod Hill, Mosquito Mound, and Pyramid Mountain. McLeod Hill and Mosquito Mound are prominent, flat-topped, steep-sided volcanoes with a typical tuya shape (see Figure 23, stage 3b). Pyramid Mountain, with its pyramidal shape, is a subglacial mound that never broke through the overlying ice cap (see Figure 23, stage 2b).

White Horse Bluff, another distinctive subglacial volcano at Wells Gray Park, has a most unvolcano-like form. The bluff is an eroded remnant that marks the place of a violent eruption, thought to have involved the following sequence of events: 1) water, likely dammed by glacial ice, filled the Clearwater River valley; 2) the water flooded down the volcano's vent, producing large explosions of steam and broken lava fragments; 3) once the explosions had subsided, these fragments settled back into the water, building up a volcano composed almost entirely of fragmental volcanic glass (hyaloclastite).

Wells Gray Park has had a long history of relatively quiet fire-fountaining-style eruptions. More violent explosions are possible only in unique circumstances, such as an eruption into a lake. Any future eruption is most likely to affect only a limited area downslope from the volcano. Poisonous gases could be expelled and, as the flows are likely to travel long distances, it is conceivable that drainage systems could be rearranged and some river valleys might be dammed. Lava flows could start forest fires as most of the region is wooded. Salmon do not swim very far into the park, but future eruptions could have an impact on the significant recreational trout fishery in the park's lakes and river. Disruption of local air traffic and tourism is possible and could represent a crowd-control hazard in this remote yet relatively accessible region.