Devils Backbone, North Fork John Day River, Grant Co., Oregon, USA
|Latitude & Longitude (WGS84):||44° 58' 49'' North , 119° 11' 54'' West|
|Latitude & Longitude (decimal):||44.98028,-119.19861|
|Köppen climate type:||Csb : Warm-summer Mediterranean climate|
Zeolites occur along the road along the North Fork of the John Day River, in Grant County, Oregon. The best site known as Devils Backbone is named after the ridge intersecting the river 12.5 miles west of Highway 395 from the Camas Creek Bridge. The site was first found in the 1960's by Isabelle Mattison when the road was made for logging. The road was gated and locked until the 1970's, when Rudy Tschernich relocated the site.
Zeolites are abundant in a hard black basalt. The basalt flows belong to the Picture Gorge member of the Columbia River Basalt Group and is of Miocene age (Radiometric date of 16.5 m.y.o.). The basalt is massive to columnar with the cavities elongated in the flow direction.
Collecting in the cliff is difficult although large boulders often fall down to the road in the winter making it easy to collect in them in the spring.
9 valid minerals.
Rock Types Recorded
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Entries shown in red are rocks recorded for this region.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
5.333 - 23.03 Ma
|Neogene volcanic rocks|
Age: Miocene (5.333 - 23.03 Ma)
Description: Columbia River Group, undivided; lava flows; mixed lithologies; basalt
Reference: R.L. Smith, W.P. Roe (compilers). Oregon Geologic Data Compilation, release 6. State of Oregon Department of Geology and Mineral Industries. 
|Middle Miocene - Early Miocene|
11.62 - 23.03 Ma
|Picture Gorge Basalt|
Age: Miocene (11.62 - 23.03 Ma)
Stratigraphic Name: Picture Gorge Basalt
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052.