Before The Collapse
Posted by: Groundspeak Premium Member Volcanoguy
N 42° 56.751 W 122° 10.118
10T E 567823 N 4755136
Geologic history sign at Wizard Island Overlook on West Rim Drive.
Waymark Code: WM7KWP
Location: Oregon, United States
Date Posted: 11/06/2009
Published By:Groundspeak Regular Member silverquill
Views: 8

Marker Name: Before The Collapse
Marker Text: When Mt. Mazama collapsed about 6,800 years ago, it left behind evidences of its former self. Like X-ray photos, the steep caldera walls reveal the interior of Mt. Mazama before its fall. From this point several pre-collapse volcanic features can be identified.
The massive gray monolith on the rim ahead is Llao Rock. It formed when a large outpouring of lava filled an explosion crater on the north slope of Mt. Mazama. When Mt. Mazama collapsed, part of the hardened lava flow broke off and fell into the caldera, leaving the downslope portion perched on the rim.
The jagged, colorful spires of Hillman Peak in the forground are the remains of a secondary volcano which erupted on the side of Mt. Mazama. This satellite cone attained a height of 1,000 feet (300 m). Erosion here has arranged a maze of clogged and solidified lava conduits that fed the Hillman volcano.

NOTE: This sign uses an age of about 6,800 years ago, while most other signs abound the park use about 7,700 years ago. This sign has not been updated to the calibrated age of 7,700 years for the eruption of Mt. Mazama to form Crater Lake.

Historic Topic: Geological

Group Responsible for placement: National Parks Service

Marker Type: Roadside

Region: Willamette Valley

County: Klamath

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

Web link to additional information: 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... Google Map
Google Maps
Bing Maps
Nearest Waymarks
Nearest Oregon Historical Markers
Nearest Geocaches
Create a scavenger hunt using this waymark as the center point
Recent Visits/Logs:
Date Logged Log User Rating  
OregonTrailRanger visited Before The Collapse 11/27/2020 OregonTrailRanger visited it
ChapterhouseInc visited Before The Collapse 07/13/2013 ChapterhouseInc visited it
bachmann_andreas visited Before The Collapse 12/12/2011 bachmann_andreas visited it
Volcanoguy visited Before The Collapse 08/25/2009 Volcanoguy visited it
Queens Blessing visited Before The Collapse 08/08/2007 Queens Blessing visited it

View all visits/logs