Large basaltic shield volcanoes throughout the central Northern Cordilleran Volcanic Province form large lava plateaus and are the largest volcanoes of the volcanic zone. These extensive volcanoes are generally larger and more long-lived than volcanoes of adjacent volcanic zones, including the stratovolcanoes of the Cascade and Aleutian arcs. Mount Shasta, the largest stratovolcano in the Cascade Arc and Mount Veniaminof, one of the largest and most active volcanoes in the Aleutian Arc, have volumes of at least , less than half of that of the Level Mountain and Edziza shield complexes. The massive Level Mountain shield, occupying an area of and a volume of more than , is the most voluminous and most long-lived volcano of the Northern Cordilleran Volcanic Province. Further south, the Mount Edziza volcanic complex resides as the seconed most voluminous volcano with an area of and a volume of . Just west of Level Mountain lies Heart Peaks, the third most voluminous volcano of the Northern Cordilleran Volcanic Province with an area of . However, remains of a shield volcano that once covered an area of more than are present in the western Cassiar Mountains as Maitland Volcano.