Blasts from the Past

Did you know there are some amazing volcanoes in the Pacific Northwest? Some of the best and most alluring volcanic sites are situated along the Volcanic Legacy Scenic Byway, a roughly 500-mile All-American Road that traverses the Cascade Range in Oregon and California. Curious about this one-of-a-kind scenic drive and the volcanoes you’ll encounter? Here’s a quick breakdown of volcano basics and the sites you’ll see on the byway.

Types of Volcanoes

You might have an image of a “typical” volcano in your head, but volcanoes have a wide and impressive variety of formations. They vary by characteristics like size, shape, eruption type and frequency, rock types, and more. For example, some volcanoes are monogenetic, erupting only once, while others are polygenetic and erupt multiple times.

The most common types of volcanoes are:

• Cinder cones: These volcanoes are “built from particles and blobs of congealed lava ejected from a single vent.” When erupting, lava is thrown into the air and breaks into chunks of cinders, which fall around the central vent to create a circular or oval cone. 
• Composite volcanoes: Composite volcanoes are also known as stratovolcanoes. They typically feature steep symmetrical slopes around a central vent or clustered group of vents. These slopes are composed of “alternating layers of lava flows, volcanic ash, cinders, blocks, and bombs.’
• Shield volcanoes: Shield volcanoes are “built almost entirely of fluid lava flows,” which create a gently sloped dome-like shape over time. This shield shape covers great distances and often features rift zones, where lava erupts through cracks in the surface.
• Lava domes: Also called volcanic domes, lava domes are “formed by relatively small, bulbous masses of lava too viscous to flow any great distance.” In contrast to shield volcanoes that spread over larger areas, lava domes build up from within, creating an outer surface that cools, hardens, and shatters.

The Volcanic Legacy Scenic Byway

You can see many of these types of volcanic formations along the Volcanic Legacy Scenic Byway that winds through the Cascade Range. Here are some of the most iconic sights along the way:

• Crater Lake, a picturesque lake in the collapsed stratovolcano Mount Mazama
• Mount Shasta, a California composite volcano that’s among the most beautiful and eye-catching in the world
• Medicine Lake Volcano, the largest volcano in the Cascades, a shield volcano that extends over 800 square miles
• Lava Beds National Monument, a network of explorable caves and lava tubes off the Medicine Lake Volcano
• Lassen Volcanic National Park, a hotspot for numerous volcanoes, mountain lakes, and gorgeous hiking trails

Here at Scenic America, we value these scenic places and want them to see them persist. We work to preserve the Scenic Byways, landscapes, and towns that define our nation’s visual character. Donate today to help us protect our beautiful places and the heart of our country’s character!