The Ancestral Deschutes River - Deschutes County, Oregon
Posted by: Groundspeak Premium Member Volcanoguy
N 43° 59.697 W 121° 23.224
10T E 629327 N 4872576
Quick Description: A geologic history sign about the ancestral Deschutes River along the Deschutes River Trail between the Meadow and Lava Island day use areas.
Location: Oregon, United States
Date Posted: 2/26/2013 10:05:10 PM
Waymark Code: WMGFFW
Published By: Groundspeak Premium Member silverquill
Views: 3

Long Description:

This sign is located along the Deschutes River Trail about a tenth of a mile south of the Meadow Trailhead.

Marker Name: The Ancestral Deschutes River
Marker Text: During the past half million years, the Deschutes River has been caught between the violence of two volcanic forces. Repeated eruptions in the Cascades pushed the river eastward while eruptions from Newberry Volcano pushed it westward. In more recent geologic times, successive lava flows forced the river to relocate farther and farther to the west.
The most recent relocation of the river and formation of Lava Island occurred 6200 years ago when Lava Butte erupted. The two river channels flowing on either side of Lava Island begin approximately a mile upstream.

This sign is 15 to 20 years old and uses 6200 years as the age of the Lava Butte flow but these are 6200 C14 years before 1950 AD. The concentration of carbon-14 in the atmosphere has varied over time and as a result C14 years are not the same as calendar years. More recent work has allowed the development of calibration curves, so today the generally excepted age for the Lava Butte eruption is 7000 years before 1950 AD. This eruption filled about four miles of the previous river canyon with lava.

An earlier eruption about 78,000 years ago filled over ten miles of river channels and diverted the river into a new channel that was more than 50 miles long before the river reentered its old channel. For more on the ancestral Deschutes River check page 58 on the web link below.

Historic Topic: Geological

Group Responsible for placement: Forest Service

Marker Type: Trail

Region: Central Oregon

County: Deschutes

Web link to additional information: [Web Link]

State of Oregon Historical Marker "Beaver Board": Not listed

Visit Instructions:

Include your thoughts and observations pertaining to this location and your visit. Provide any additional history that you are aware of that pertains to this location. If the marker commemorates a historic building tell us what it is used for now or share with us the circumstances of an earlier visit to bring this locations history to life.

Please upload a favorite photograph you took of the waymark. Although visiting this waymark in person is the only thing required of you to receive credit for your visit, taking the time to add this information is greatly appreciated.

Be creative.

Search for...
Geocaching.com Google Map
Google Maps
MapQuest
Bing Maps
Nearest Waymarks
Nearest Oregon Historical Markers
Nearest Geocaches
Nearest Benchmarks
Create a scavenger hunt using this waymark as the center point
Recent Visits/Logs:
Date Logged Log User Rating  
Volcanoguy visited The Ancestral Deschutes River - Deschutes County, Oregon 2/17/2013 Volcanoguy visited it