The Milbanke Sound Group in the Kitimat Ranges consists of young lava flows and monogenetic cinder cones that were probably formed in the last 10,000 years. Like Silverthrone and Franklin, little is known about the Milbanke Sound Group. As a result, its affinity also remains unclear. It may reflect a northern extension of the Garibaldi Volcanic Belt, but there is not enough data to support this hypothesis. Its formation might have also resulted from other tectonic processes that are currently not understood. Swindle Island contains a high symmetrical cinder cone on its southern shoreline. This volcano, known as Kitasu Hill, comprises tephra and volcanic bombs. Its summit contains a volcanic crater that is breached to the east. Helmet Peak, a steep-sided cinder cone on Lake Island with an elevation of , consists of welded volcanic blocks and basaltic feeder dikes. During eruption, basaltic tuff breccia was deposited throughout Lake Island and nearby Lady Douglas Island. Lava flows on the shores of Price Island and Dufferin Island were erupted from forest-covered basalt cones, which have been reduced in size to small volcanic mounds. Basaltic lava flows on Finngal Island comprise well-developed columnar jointing. Like other volcanic deposits in the Milbanke Sound Group, very little is known about these lava flows. Although the Milbanke Sound Group was probably formed in the last 10,000 years, the exact age of the lava flows and cinder cones is unknown. It probably formed in the last 10,000 years because the volcanic formations have minimal erosion, indicative of post-glacial volcanism.