For 100 years, the National Park Service has preserved America’s special places “for the enjoyment, education, and inspiration of this and future generations.” Celebrate its second century with the Find Your Park GeoTour that launched April 2016 and explore these geocaches placed for you by National Park Service Rangers and their partners.
geocaching.com/play/geotours/findyourpark
Getting to the cache: This cache is located on the Big Nasty Trail, a 2.0 mile loop trail with rocks in the path, steep sections, and two fallen trees you must climb over. To access the trail, park at the Mammoth Crater parking area and you will find the trail head on the way to Mammoth Crater. Please keep in mind that weather conditions vary and the trail can accumulate ice and snow. You will be walking through open brush and ponderosa pine forest. No matter the season, plan on bringing a hat, sunscreen, and plenty of water. This trail leads into Lava Beds Wilderness: please review and comply with wilderness regulations!
Remember that you are in a National Park Service site.
- All plant material, rocks, animals, and historical features are protected by law and may not be collected or disturbed.
- Please practice Leave No Trace
- Safety information: Although not commonly encountered, watch out for bears, mountain lions, and rattlesnakes.
- Lava Beds National Monument Visitor Center information:
- Address: 1 Indian Well HQ, Tulelake, CA 96134
- Phone Number: 530-667-8113
- Website: www.nps.gov/labe
- In an emergency: dial 911
Geological Information:
You are on the Medicine Lake Volcano, a shield volcano within the Cascade Range. Lava Beds National Monument makes up about 10% of the volcano.
Walking along the Big Nasty Trail takes you around Mammoth Crater, one of the sources for the lava flow that coves ~70% of the monument. Mammoth Crater was a lava lake that erupted and overflowed approximately 36,000 years ago.
The Basalt of Mammoth Crater is just one of over 30 lava flows in the monument. These lava flows range from about 450,000 years old to as young as 1,120 years old. The youngest lava flow, the Callahan Flow, is seen off to the west from this point. This aa lava flow is sourced from a vent that created Cinder Butte, a cinder cone.
Cinder cones are formed when volcanic vents spew out hot lava fragments into the air when gas expands as it nears the surface. These lava fragments, also known as scoria or cinder, are shot into the air, where they begin to cool and solidify before they reach the ground. The fragments then fall down to the ground to form a cone. Scoria is very vesicular: as it is ejected into the air, it begins to cool with gasses trapped inside. Scoria is often red, brown, or black. Another common kind of vesicular volcanic rock is pumice. Pumice forms from a more felsic, or silica rich, lava in a similar way to that of scoria. Pumice is a grayish, frothy volcanic glass.
Off in the distance you will see a cinder cone that sticks up above, and is surrounded by, the Callahan Flow, making it a kipuka. A kipuka is an area of land surrounded by a younger lava flow, kind of like an island. As a result of these features, this cinder cone is called Island Butte. Notice that Island Butte has much more vegetation than the surrounding lava flow. This is because it is older and because it is well protected by the Callahan Flow.
To log this cache, send an email with the answers to the following questions: Is there pumice or scoria along this trail? How many cinder cones can you see from this GPS point?
For more information on the geology of Lava Beds, see our Geology Brochure and find out more information on planning your visit by visiting www.nps.gov/labe.
Approved by Patrick Taylor, Chief of Visitor Services at Lava Beds National Monument. Contact: 530-667-8113