Knowledge you can walk. Read the idea below, then step up to the general, across to peers or down to the specific.
Physical
Beacon Rock
Beacon Rock is an 848-foot basalt volcanic plug on the north shore of the Columbia River in Washington.
Learn, discuss, create, buy or invest
The idea
Beacon Rock is a huge, steep-sided tower of dark rock that stands beside a wide river. It rises 848 feet (258 m) and is made of basalt, a volcanic rock that forms when molten rock cools. Geologists call it a volcanic plug. A plug forms when magma cools and hardens inside the pipe that once fed a volcano. Plug rock is often harder than the surrounding rock, so erosion can gradually strip the softer material away and leave the plug standing alone.
The rock stands on the north shore of the Columbia River, in Skamania County, Washington, about 32 miles (51 km) east of Vancouver. It gives its name to Beacon Rock State Park, a geologic preserve and public recreation area on Route 14. The park sits inside the Columbia River Gorge National Scenic Area.
The rock also has a place in the history of American exploration, because the Lewis and Clark Expedition stopped here on its journey west. At this spot the explorers first measured tides on the river, and the rising and falling water told them that they were nearing the ocean.
Check yourself
Question 1 of 3
What kind of landform is Beacon Rock?
Composition
what it's made of
- Basalt — The dark volcanic rock that the whole tower is made of.
- Volcanic plug — The type of landform: magma that hardened inside the vent of an old volcano.
- North shore setting — The rock stands on the Washington side of the Columbia River, in Skamania County.
- Beacon Rock State Park — The geologic preserve and public recreation area named after the rock.
Connection
how it relates
Change
how and why it evolves
- Past
- On October 31, 1805, the Lewis and Clark Expedition arrived at the rock and first measured tides on the river. Henry J. Biddle bought the rock in 1915 for $1 and over the next three years built a trail with 51 switchbacks. Washington at first refused the Biddle family's gift, but the park was finally established in 1935.
- Now
- Climbers know Beacon Rock for challenging technical rock climbing, and trails lead hikers to the top of the rock.
- Next
- Hard basalt wears down very slowly, so the rock will probably look much the same for a very long time, while the park keeps balancing visitors with protection.