Home
Map
Browse Map
Explore away
Explore Map Collection
Check out our basemaps
Print a Map
Plus
Generate a high-quality PDF
Field Guide
Field Guide
Discover local flora, fauna, geology, and more
Local Flora & Fauna
Learn the ecology of your area
Local Geology
Learn the geologic formation at your feet
Get Started
or
Sign In
Welcome
Sign up to start exploring the one-of-a-kind Natural Atlas Topo map
Continue with Apple
Or
Sign up with Email
Already have an account?
Sign In
MAP
Topo
Waterfalls
Rock Formations
Campgrounds
Trails
Boat Launches
National Parks
State Parks
Scenic Spots
Measure
You must upgrade to measure routes
Start Free Trial
0 ft
Max
0 ft
Copyright
© Natural Atlas
| Roads, Buildings
© OSM Contributors
|
Data Sources
Topo
Ecoregions
Public Lands
...
BASEMAPS
Default Weather
Temperature
Smoke
...
WEATHER
Three Fingered Jack
Shield Volcano
in
Deschutes NF
,
Mount Jefferson Wilderness
,
Cascade Range
near
Camp Sherman
,
OR
Print Map
Generate High-Quality PDF
On the Web
On Wikipedia
Three Fingered Jack, named for its distinctive shape, is a Pleistocene volcano in the Cascade Range of Oregon. It is a deeply glaciated shield volcano and consists mainly of basaltic andesite lava. Compared with other heavily glaciated volcanic peaks such as Mount Washington and Mount Thielsen, which display eroded volcanic necks as their cores, Three Fingered Jack's present summit is a narrow ridge of loose tephra supported by a dike only 10 feet (3.0 m) thick on a generally north–south axis. Radiating dikes and plugs from a series of overlapping cinder and composite cones that support this summit have been exposed by glaciation. The sole glacier is the unofficially-named Jack glacier, located in a shaded cirque on the northeast side at an unusually low altitude for the Oregon Cascades.…
Read More on Wikipedia
Taxonomy
Classified As
Shield Volcano
Geologic Formation
Mafic vent complexes (ORQTmv;0)
Geologic Formation
Search
Search the outdoors
Map
Plans
Field Guide
Community
My Profile
My Trips
0
My Field Notes
0
Notifications
More