South Sister lava flows, USGS

"Aerial view of the south flank of South Sister composite volcano showing numerous blocky lava flows erupted about 2,000 years ago. Early eruptions formed Rock Mesa (just above center, far left), a broad flat flow emplaced on nearly level ground. Subsequent eruptions formed a line of lava domes and flows that extend from Sparks Lake meadow (lower right) to Green Lakes (just above center, far right). Several small lava domes were also formed on the northeast flank, out of view. Cratered cone in lower left is Talapus Butte, a basaltic scoria cone."