The Hat Creek area is a lava-tube province rather than a single cave locality. The important cave belt is associated with the young Hat Creek Basalt, which erupted from fissures south of Old Station and sent lava roughly 20 km northward through a system of lava tubes. USGS estimates the flow covered nearly 100 km² of the Hat Creek Valley. (USGS Publications)
Major cave areas
Old Station / Subway Cave area
This is the best-known and most accessible portion of the Hat Creek lava field.
Subway Cave is a roughly 1,300-ft lava tube formed in the Hat Creek flow. The Forest Service describes it as the largest accessible tube in the flow. The tube is generally 6–17 ft high, with a roof roughly 8–24 ft thick. (USDA Forest Service)
The important thing for a caver is that Subway is not representative of the entire Hat Creek cave resource. It is the developed show/access cave; the surrounding lava contains many additional tubes, skylights, collapses and smaller caves.
The junction of CA 44 and CA 89 at Old Station is a useful geographic reference point.
Spatter-cone / source-vent zone
Southwest of Old Station is the Spattercone Trail / Hat Creek Basalt vent area.
This is particularly interesting to a caver because you’re getting toward the source of the lava system, where fissures and spatter cones fed the extensive tube-forming flow. The Forest Service describes the Hat Creek lava as having erupted from a series of north-south fissures, with the lava subsequently traveling northward beneath a cooling crust. (USDA Forest Service)
The Spattercone area contains:
- spatter cones
- lava fissures
- collapse features
- small lava tubes
- skylights
- inflation structures
It is therefore more of a lava-tube exploration landscape than a single large-cave destination.
Central Hat Creek lava-tube belt
This is the most interesting zone if you’re thinking like a cave surveyor rather than a tourist.
Historical work by the Shasta Area Grotto documented a surprisingly large cave inventory in the Hat Creek flow. A 2002 cave list contained 85 named caves, with another 12+ awaiting survey, totaling 28,469 ft (5.4 miles) of surveyed passage at that time. (SAG Caves)
The largest listed caves were:
| Cave | Surveyed length |
|---|---|
| Subway Cave | 2,781 ft |
| Rusty Cave | 2,714 ft |
| Elisha Cave | 2,028 ft |
| Christmas Tree Cave | 1,987 ft |
| Wilcox Cave | 1,175 ft |
| Arc Cave | 850 ft |
| Jay Feather Cave | 783 ft |
| Bat Mummy Cave | 762 ft |
| Christmas Tree North Cave | 738 ft |
| Alien Space Cave | 706 ft |
Those figures are from the 2002 Hat Creek cave inventory, so they should be treated as a historical survey snapshot, not necessarily the current extent of the caves. (SAG Caves)
Elisha–Daycrawler–Miller Time cluster
This deserves special mention because it illustrates how the Hat Creek caves can form interconnected or genetically related tube complexes.
Elisha Cave is about 2,028 ft long and is described by the Shasta Area Grotto as an important Hat Creek lava tube. It contains large passages, breakdown areas, upper-level passages, lava formations and a room roughly 60 ft wide and more than 100 ft long.
Nearby Daycrawler Cave is about 598 ft long and has three entrances. Its passage is largely easy walking, with an upper-level passage and multiple entrance sinkholes. The 2002 survey work concluded that Daycrawler represents an upflow precursor to Elisha.
Miller Time Cave is only about 183 ft long but is closely associated with Elisha; the published description actually calls it an overlying cave relative to Elisha. (SAG Caves)
This group is particularly valuable geologically because it demonstrates the multi-level development of the Hat Creek tubes. When a lava tube becomes partially blocked, lava can divert around or above the obstruction, producing parallel and perched passages.
Christmas Tree Cave area
Christmas Tree Cave, at approximately 1,987 ft in the 2002 inventory, was the fourth-longest listed Hat Creek cave. (SAG Caves)
There is also a Christmas Tree North Cave, listed at 738 ft, indicating that this isn’t simply an isolated tube but part of a broader concentration of lava-tube development.
This is one of the areas I’d consider particularly important for understanding the distribution of the larger Hat Creek tubes, although detailed entrance locations should be taken from current grotto/Forest Service survey information rather than reconstructed from generalized maps.
What Makes Hat Creek Unusually Good Cave Country?
The geology is ideal for lava tubes.
The Hat Creek Basalt is a relatively young basaltic flow, approximately 24,000 years old, that originated from fissure vents south of Old Station. Up to about 2.5 km³ of lava was transported northward, much of it through lava tubes. (USGS Publications)
The basic sequence was:
fissure eruption → lava river → crust forms → interior remains molten → lava drains → tube remains → roof collapses locally
That explains why the surface is covered with skylights, sinks, collapse trenches and small entrances, while substantial portions of the original tubes remain underground.
The National Park Service describes this general process as the normal mechanism for formation of lava tubes: an insulating crust forms over flowing lava while molten material continues moving beneath it. (National Park Service)
The important caving pattern
A useful way to visualize Hat Creek is:
south → north
Spatter-cone/fissure source area
↓
young, fluid lava
↓
major feeder/tube systems
↓
multi-level tube complexes
↓
collapse/skylight zones
↓
Subway and other accessible remnants
↓
farther north along the Hat Creek flow
A particularly important distinction
Hat Creek should not be confused with Lava Beds National Monument farther north/east. Lava Beds has a much larger concentration of documented caves, but Hat Creek has its own substantial lava-tube system. The Volcanic Legacy Scenic Byway describes the Hat Creek lava deposits as one of California’s largest lava fields and specifically identifies the numerous lava tubes and collapse features around Old Station. (Volcanic Legacy Byway)