A Visit to North Table Mountain, Oroville, California
North Table Mountain Ecological Preserve
As you drive north on Highway 70, seven miles past the town of Oroville, California, a structure in the distance begins to pique your interest. At first you think it is just a low mountain, but as it takes shape, you can see it is a winding wall of rock sitting level to the horizon. This is Table Mountain, an ecological preserve managed by the California Dept of Fish and Wildlife.
Being an ecological preserve makes it special, but so do many other things. For starters, it is an icon from an era long past. The structure is vast, meandering, and is topped by a semi-flat surface. If you watched Close Encounters of the Third Kind, you have sort of seen the basic shape. The difference between that mountain and Table Mountain is how it was created. The mountain in Close Encounters is the magma chamber of an old volcano; the mountain around the volcano eroded leaving only the old solidified magma. Table Mountain is lava, not magma. Magma is never extruded from a volcano; once a volcano erupts, the magma forced out of it becomes lava, with a different texture. The crystals or grains within magma are larger because of the extended period of time they spend at high temperature. Lava, though super-hot, cools off really rapidly compared to magma. So when you look at an igneous rock, you can usually tell how it was formed. Small grains mean it cooled off quickly as lava; larger crystals usually mean the magma cooled off slowly, deep underground. Granite is a good example of solidified magma.
Table Mountain is made up of fine-grained basalt, the same rock type that makes up much of the ocean floor. Table Mountain is the geological result of an enormous volcanic eruption. The lava spewed forth and filled up the valley between mountains. Those mountains are long gone, thanks to erosion of their softer rock, and what remains is a table-like structure made up of extruded lava. Basalt is fairly hard and it erodes away slowly. As you look through the pictures, notice the size of the rocks. This is a remarkable site, not just because it is an ecological preserve, but because it has a vast and wonderful history.
Spring Flowers of Table Mountain
The Ecological Preserve
In California we are struggling to preserve native species of plants, animals, bees and other insects, and other organisms. California's rich history tells the tale of how California's changing human population introduced invasive plants, animals, and organisms. The California of today is not nearly as grand as the California of the past. Coastal redwood (Sequoia sempervirens) forests once stretched to San Francisco and throughout the East Bay area up through Oregon. Today a minuscule percentage of old-growth coastal redwood forests remain. That is quite a sad thing because these trees which can grow nearly 400 feet into the air can also live for thousands of years. These forests of ancient trees were logged because of the vast amount of lumber that one tree could provide; the economic value within a single old-growth tree is tremendous. Even today, there are battles over whether or not we should continue to log old-growth timber. Because these trees can live to be 1800 years old or older, ethically managing a grove of redwoods would require the cooperation of not just our generation, but 18-20 generations of humans.
Ranching and agriculture have also taken a huge toll on the ecology of California. Gone are the native bunch grasses that once covered the valley. Fencing disrupted the natural migration of the pronghorned antelope and the tule elk. Wetlands have been filled in to make more agricultural land and with the loss of habitat a vast treasure of native plants and animals have gone. One of the biggest threats to California's ecology today, is global warming. Native plants and animals live in very specific temperature zones. Many can't adapt nearly as fast as humans to a changing climate.
It is because of these kinds of losses that Table Mountain is important as an ecological preserve. The unique soil structure makes it nearly impossible for invasive plants to take root. That means when you walk through the preserve, you see a reflection of the past. Table Mountain is an excellent spot for scientific research, not only for botanists, but also for many different branches of science. It is also a place where the public can go and see the beauty that can exist if we care for our resources.
This unique geological structure has created a unique habitat where very specialized plants can thrive without the pressures that invasive species add to their reproductive cycle. It is a trip that will blow your mind.
When to Go
Table Mountain shares California's Mediterranean climate. In a normal weather year, the rainy season is October through March or April is the rainy season. This means that winter and sSpring are the best times to go. These photographs were taken on 21 March 2014. If the rains have come on time, February, March, and April would be ideal months to visit Table Mountain.
If the winter has been mild, you might also get lucky in January. A lot of this depends on the amount of quality sunlight that is able to strike the ground.
To get there:
- Take Highway 70 to Oroville.
- Take Exit 48 which is Grand Avenue.
- Turn right on Grand Avenue for approximately 1 mile.
- Turn left onto Table Mountain Boulevard and travel about 1/10 of a mile.
- Turn right onto Cherokee Road.
- In 6.3 miles, you will find the small parking lot at Table Mountain and the official entrance to the preserve. There are cattle gates that you are free to use to gain access.
North Table Mountain, Oroville, CA
What to Look for
First, if you are a novice adventurer allow me to recommend the guided wildflower tours. These guided hikes are an excellent way to learn about the wildflowers that you will see and the remarkable history of this beautiful preserve.
Wear sturdy shoes. The place is littered with "ankle-rollers," the fractured basalt rocks that are the perfect size to twist your ankle. In March, the rattlesnakes are also out. They typically hang out in the really sunny hot places, but you can encounter them all throughout the preserve. There are not real trails within the preserve so you can wonder about. Cattle on the preserve, which are used to help keep invasive grasses out, have made trails and those work well for hiking. The Department of Fish and Game suggests not approaching the cattle closer than 300 feet.
What to look for:
Vernal pools, wildflowers, and geological structures are three of the biggest things that people discover here. Be prepared to move slowly because every square meter of ground has something remarkable to view.
Into the Dell
Fields of Color
Example: Vernal Pools at Jepson's Prairie
The vernal pools found on Table Mountain are very special ecological structures, getting rarer every day in California.
A good term to describe them would be "island ecosystems." A vernal pool is like an island within another ecosystem. It contains specialized plants and organisms that do not exist outside of the pool. If you truly want to enjoy the vernal pool, lie on your stomach at the edge of the pool and be really still. As you peer into the water, notice the plants, and then you will likely notice things such as fairy shrimp. An amazing world is contained and isolated within each pool.
Vernal pools are created by an impression in the ground where a hardpan layer of clay allows water to pool. These are not permanent pools; the water comes during the rainy season, and then it dries up during the summer. So life in a vernal pool starts the moment the first raindrop hits the dry pool.
There are four phases to a vernal pool that occur each season:
- The wetting phase where water begins to accumulate.
- The aquatic phase where water is at its peak height.
- The drying phase where water is mostly evaporated and the ground is soggy.
- The dry phase where all of the water is gone and the soil is dry.
Because the life of a vernal pool is usually just a few months long, the plant and animal life within a vernal pool must be able to adapt to drastic changes. The plants must cycle between being completely dry and being completely aquatic. Most of these plants we call emergent because they emerge out of the water to bloom. Their lives may be only a week long, but they are able to grow, bloom, and develop seeds, thanks to their pollinators.
Vernal pools at Table Mountain are created by small depressions in the basalt. Cracks within the structure hold water during the wet season, and as streams and off-flow occur, the vernal pools here come alive. Try not to trample through the pools. Instead, just enjoy them from the edges.
You can spot a vernal pool by what botanist call bathtub rings. These are bands of flowers, often brilliantly colored, growing in a ring around the edge of the pool. As the water begins to dry up, different species bloom, week by week, in newly exposed rings.
Sky Lupine, and Sky
Notice how thin the soil layer is. This basalt lava is breaking down very slowly. It creates a special growing area for California native plants.
Mid-Way Down the Dell
A seasonal stream partway down the dell. There is a waterfall later on..
The Start of the Waterfall
Up the Dell
The Edge of an Oak Woodland
Heading back to the Parking Lot
A Closer Look at Flower Species on Table Mountain
A closer look at the fields of blue, pink, orange, yellow, and white on Table Mountain reveals individual native species.
Mimulus, Lupinus, Eschscholzia, and Castilleja
Johnny Tuck and Sky Lupine
Tufted Poppy with Common Goldfields
What to Bring to Table Mountain
Lunch, water, and sunscreen are a must. Optional stuff includes:
- Camera (you will want to take pictures) with a macro setting. Most of the photos in this article were taken with my iPhone.
- Binoculars if you want to view wildlife and birds. If you sit in a spot for a while, you will begin to notice the birds and animals.
- A hand lens, if you are interested in looking at tiny plants. Most of the plants here are small. Within the vernal pools, you will likely see micro-plants that you can enjoy using a hand lens.
- Dress in layers, as the weather can range from chilly to hot to stormy quickly. A wide brim hat with a chin strap is also recommended, plus sturdy shoes that support your ankle.
- Bug repellent that is approved for use against ticks.
What Not to Bring
- Dogs or other pets
- Plant- or animal-collecting equipment