The Pinnacles is a great little hike for those who are up for trekking off the beaten path and away from the crowds of Crater Lake National Park. The trail is flat, less than a mile long and offers a nice, relaxed hike with awesome views of the Pinnacles. Described best by one of the National Park's interpretive boards:
"The history of the Pinnacles began when the eruptions of Mount Mazama were reaching their climax 7,700 years ago. Floods of red-hot, gas-charged pumice poured down Mazama's slopes at speeds reaching up to 100 mph (160 kph). In addition to pumice, flows of heavier rocks called Scoria also tumbled out. These glowing avalanches flooded down slope for miles, leaving deep deposits in their wake.
Temperatures in the deposits may have exceeded 750 F (400 C). Plumes of vapors appeared, and gasses escaped from the settling rocks through vents called fumaroles. In the extreme heat, minerals in the gasses welded the sides of the fumaroles in the shape of slender cones. Since then, streams have eroded a canyon through the deposits, exposing the cones. Many of these fossilized fumaroles are hollow."
Note: East Rim Drive is closed during the winter.