WARNING AS OF 2022: As a worker in the forestry and fire industry, I can confirm that this place is dangerous to visit. I first visited this area while reporting on the Dixie Fire of 2021. This area burned up in that fire, leaving all dead trees that are extremely sucestible to falling with the slightest wind or even no wind at all. Use extreme caution if you choose to visit, and never camp amognst dead trees. There are often no warning signs before dead trees fall. Below is a quote from Geocaching user remsz, who was the first to visit the earthcache site since I went:
"My assessment of the hazards comes directly from my job to assess and to respond to risks, and I do hope that anyone considering to find these two EarthCaches takes my warning to heart. This area is in the center of a section burned over by the Dixie Fire of 2021 and every single tree has been completely burned from ground to tip, with many hollowed out from the fire. Under no circumstances should anyone walk through this area during any sort of wind, and everyone should strongly consider wearing a hard hat because these trees will fall at some point. The road going to the caches is unmaintained and some of the downed trees have been cut to clear the road, but I did have to use four wheel drive and did drive directly over a small downed tree which could have greatly damaged my truck. With me, I carried my Park Service radio which accesses all the emergency channels for the NPS and Forest Service, as well as a personal locator beacon with the same connections. I spent a maximum of fifteen minutes in the burn area and moved as quickly as possible to gather enough information at the sites to then answer once I was out of the hazard section.
I hope my message about the hazards is clear and can inform safe geocaching in the future. This area must have been a beautiful place to walk before the fire, but now it needs time to heal."
Lassen National Forest is home to many volcanic features, boggling minds of many for generations.
This cache highlights the lava field, tucked back here in a corner of the Lassen National Forest that not many people visit. Getting there can be tricky, but the adventure is well worth it. I visited on the last day of July in 2021, and made it there in my 2WD Toyota Tacoma. However, just to be safe, I’d recommend 4WD to get there!
“[To get there,] take highway 36 to Wilson Lake Road 29 & 63, then make a right onto the 29 N 19 road. Next, find the E. Spur Road off of 29 N 19, and if you’re lucky, you’ll stumble upon a tree marked ‘Ice’ in blue paint. From there just ahead you will find an opening with a couch carved out of a tree, a trailhead, and a mailbox attached to a tree with a beautiful guest book inside. It’s kind of like stumbling upon a hidden door you never knew was there” (Dobyns, 2017).
Remember to sign in at the mailbox! Not only is it fun, but it is actually a safety precaution. Should anything happen to you out on the hike, a sign-in at the trailhead leaves a recorded step about your last whereabouts, and how long you’ve been out there (therefore, signing out is encouraged as well). There is little to no cell service out here, so know where you’re aiming to get to before you make the trek out here.
This lava field is a result of a surface lava flow of mainly basalt igneous rock. Observing a lava field from the surface can offer clues into how it formed and what may lie beneath. For instance, ridges or patterns formed by the pieces of rock can reveal the direction of channels or even if there’s lava tubes underneath it or not. This outer, top layer of a lava field is called the crust.
There are two main types of lava flows which when dry, result in lava fields. The main types are pāhoehoe flows and ʻaʻā flows. Pāhoehoe means “smooth,” so these lava flows are identified as having a smooth, billowy surface. These lava flows typically have a low viscosity, and are able to flow faster.
ʻAʻā flows are characterized by rough surfaces and broken, blocky chunks of lava rock. These loose, sharp pieces of lava rock are known as clinkers. It is much thicker and slower-moving that the pāhoehoe flows.
Interestingly enough, as a pāhoehoe flow cool sand travels further away from its source, its viscosity increases and it can actually turn into an ʻaʻā flow. The lava cools down and no longer can flow smoothly like butter, but begins to harden and clump up and produce jagged rock clinkers.
A lesser common type of lava flow is called block lava flows. It is similar to an ʻaʻā flow, but more viscous. The lava is also covered in more smooth-sided blocks, rather than the jagged, rough clinkers of an ʻaʻā flow. They move much more slowly and are usually thicker than the other types of flows.
To log this Earthcache, please send me a not with the following:
- Name of this Earthcache and number of people in your group (even those are not caching!)
- Touch some of the rocks around you. Are they smooth or rough?
- Observe the rocks that make up the lava field all around you. What type of flow do you think this more closely resembles? Pāhoehoe, ʻaʻā, or block?
Enjoy! Please respect this area by removing any trash you bring in or see out there on the trail. Thank you.
Sources:
http://worldlandforms.com/landforms/lava-field
https://en.wikipedia.org/wiki/Lava_field
https://www.fs.usda.gov/detailfull/lassen/maps-pubs/?cid=fseprd533813&width=full
https://en.wikipedia.org/wiki/Lava_cave
https://en.wikipedia.org/wiki/Lava#Pāhoehoe
https://www.mountainvalleyliving.com/2017/01/exploring-ice-caves-in-lassen-county/
https://www.nps.gov/subjects/caves/lava-caves-or-tubes.htm
http://www.geo.cornell.edu/geology/GalapagosWWW/LavaTypes.html