Shastina is the highestsatellite cone of Mount Shasta, and one of four overlapping volcanic cones which together form the most voluminous stratovolcano in the Cascade Range. At, Shastina is taller than Mount Adams and would rank as the third highest volcano in the Cascades behind Mount Rainier and Shasta were it not nestled on the western flank of its higher neighbor. Shastina has a topographic prominence of over above the saddle connecting it with Shasta and easily exceeds the typical mountaineering standard of for a peak to qualify as an independent summit, yet most lists of Cascade volcanoes omit it nonetheless. The name "Shastina" is a diminutive of Shasta. Shastina was formed during a VEI-4 eruption around 7650 BC that also involved activity at the summit of Mount Shasta and the Red Banks on Shasta's south flank.
Shastina has the general form of a smooth-sided cone truncated by a one half-mile diameter summit crater, but with several geological features which make it unique among other volcanoes in the Cascade Volcanic Arc. The most prominent feature when seen from lowland viewpoints is Diller Canyon, a large cleft carved into the western flank by pyroclastic flows and since expanded by erosion. It extends from the crater rim near down for over 7,000 vertical feet towards the town of Weed in the valley below, and is by far the largest such feature found on any of the Cascade volcanoes. Unseen except by mountaineers and fliers are the three small crater lakes nestled among the cones and ridges of the summit crater, which rarely melt free of snow until late summer. Clarence King Lake at occupies the center of the crater, while Sisson Lake lies at on the eastern side. Highest of all is an unnamed lake at over on the south side of the cinder cone which forms Shastina's true summit. These lakes are the highest subaerial lakes in the entire Cascade Range, exceeded only by the lake beneath the ice of Mount Rainier's summit crater.
Climbing and skiing
Shastina is most commonly and easily climbed via the Cascade Gulch route, which ascends from Hidden Valley diagonally up to the Shasta-Shastina saddle, and then continuing up the eastern flank of Shastina's cone to its summit. For most mountaineers, it represents only a quick side trip on the way back from the main objective of climbing Shasta. But for ski mountaineers, Shastina represents an attractive objective of its own quite separate from the main peak of Shasta, since it provides several exceptional ski descents including Diller Canyon, the North Face, and the South Face.
