Mount Rainier is classified as a stratovolcano, also known as a composite volcano. While it shares some similarities with shield volcanoes, like the presence of lava flows, there are significant differences.

Here's a breakdown:

Similarities with Shield Volcanoes:

* Lava flows: Both types of volcanoes produce lava flows, although the composition of the lava may differ.

* Large size: Both shield and stratovolcanoes can be massive structures, often exceeding several thousand feet in height.

Differences from Shield Volcanoes:

* Lava viscosity: Stratovolcanoes produce viscous lava that is thicker and flows more slowly than the thin, fluid lava of shield volcanoes. This results in steeper slopes and a more conical shape.

* Explosive eruptions: Stratovolcanoes are known for their explosive eruptions due to the high viscosity of their magma, which traps gases. Shield volcanoes, in contrast, have effusive eruptions that release lava with less force.

* Composition: Stratovolcanoes are typically composed of alternating layers of lava flows and pyroclastic material, such as ash and pumice. Shield volcanoes primarily consist of lava flows.

* Shape: Stratovolcanoes have a steep, conical shape, while shield volcanoes have a broad, gently sloping shield-like shape.

In summary, while Mount Rainier shares the presence of lava flows with shield volcanoes, its thick, viscous lava, explosive eruptions, and layered composition make it a distinct type of volcano: a stratovolcano.