First, a little history.

Since the mid-1800s, large portions of the grasslands that once spanned California's nearby San Joaquin Valley, have been converted to agricultural, industrial, and urban land uses.  Though some of these uses have taken place in the monument years ago. It is now the largest undeveloped remnant of this ecosystem, providing crucial habitat for the long-term conservation of many native plant and animal species that inhabit the area.

Surface ownership within the monument boundary is a mixture of the BLM, The State Department of Fish and Game, The Nature Conservancy and other private owners.  The BLM, the California Department of Fish and Game and the Nature Conservancy are the monument’s managing partners.

On January 17, 2001, the President of the United States signed a proclamation designating the former Carrizo Plain Natural Area, as a National Monument. 

Even today, the Carrizo is one of the best kept secrets in California. The monument receives about 30,000 visitors annually, most from December through May. Although it’s only a few hours from Los Angeles, the Carrizo offers visitors a rare chance to be alone with nature. Some visitors say you can “hear the silence.” 

While you drive throughout the monument you may see numerous hawks, lizards and other wildlife, and if you are here during the spring, you may be fortunate enough to see a beautiful wild flower display.  No matter what the season, the saying: "The closer you look, the more you see" is certainly true. 

The monument offers refuge for endangered, threatened, and rare animal species, such as the San Joaquin kit fox, the blunt nosed leopard lizard, and the giant kangaroo rat.  In small pools of water, you may be fortunate enough to see: the long horn fairy shrimp, and the vernal pool fairy shrimp.  It supports important populations of pronghorn antelope and tule elk, and was the first place in California where these two native species could once begin to roam together.  The area is also home to many rare and sensitive plant species, including the California jewelflower, the Hoover's woolly-star, the San Joaquin woolly-threads.  Despite past human use, the size, isolation, and relatively undeveloped nature of the area make it ideal for long-term conservation of the dwindling flora and fauna characteristic of the San Joaquin Valley region.

You may ask how did the Carrizo get its name?  Well, one speculative story is that when the early Settlers came to the plains they called it, "llano estero" referring to a salt marsh plain.  Then later, as others came to the plains, the name changed to "Carrizo Plain."  The word "Carrizo" referred to a grass that grew very tall.  It was said that the grass touched the bellies of their horses as they rode across that plains.  Then as more settlers came the name change once again to Carrisa.  "Carrisa Plains" was used up to the time that the managing partners acquired the land.  A decision was then made by the partners to return to the earlier name and called it the Carrizo Plain.

Other information about the name and spelling came from the first post office on the Carrizo Plain which was founded in 1882 and was located at the El Saucito Ranch, which is located west of the visitor center a couple of miles.  Now let's talk a little bit about the farming and ranching history.  

As you drive through the plain, you may see remnants from the farming and ranching efforts on the plains.  One of the first rancing operations took place at the historic El Saucito rance.  Ranch tours can be scheduled through the visitor center.

Much of the Carrizo was dryland farmed.  Wheat and barley were the two main crops.  Occasionally safflower was planted.  After the harvest, the "stubble" was grazed mostly by cattle, but also by sheep.

Because of the unpredictable weather and rainfall, some years farmers had great crops but many years crops were marginal.  It was often described by the old ranchers as boom or bust!

You'll continue to see cattle and sheep grazing as you drive around the monument.  There are still some large, private ranches within the monument boundary that continue to graze cattle and do some limited farming.  The managing partners continue to use grazing on public lands as a tool when there is an overabundance of non-native grasses.  Grasses and other exotic weeds can choke out some of the sensitive species we have been mandated to manage for.

At our first stop starting here at the Soda Lake Overlook we will make a loop through the northern end of the monument visiting Soda Lake, the Visitor Center, and the San Andreas Fault.  This is just a small portion of the monument so you may want to do some more exploring on later visits.  

If you walk up he trail to the top of the Soda Lake Overlook, you can see some of the geologic features of the monument. 

The Carrizo Plain encompasses two plains: the Elkhorn and the Carrizo.  The Elkhorn Plain, nearly 20 miles long and two miles wide, lies at the base of the Temblor Range that you see to the northeast.  The elevation of the Elkhorn Plain ranges from 2,300 feet at the southern end and gently rises to 2,500 feet toward the north where it gradually terminates with the San Andreas fault.   

The Caliente Range, rises to 5,104 feet, is a prominent backdrop to the southwest, while the Temblor Range to the northeast rises to about 4,300 feet. The southern end of the Caliente Range bends east to parallel the Transverse Ranges.

During earlier periods of geologic history, runoff from the Carrizo Plain drained north via the ancestral Salinas River.  Since then, uplift at the north end of the Carrizo Plain has cut off this drainage causing all runoff to drain to the lowest part of the plain - Soda Lake. 

We’ll explore the geology a little more when we get to Wallace Creek.

Soda Lake is the largest remaining natural, alkali wetland in southern California and the only closed basin within the coastal mountains.  Evidence suggests that a river ran through the plains first flowing north to the ancestral Salinas River and then with uplifting from the fault the flow reversed and flowed south.  With time and more uplifting outlets were cut off and Soda Lake was formed as an internal basin.  As its name suggests, Soda Lake concentrates salts as water is evaporated away, leaving white deposits of sulfates and carbonates that look like baking soda.  Sodium sulphate was recovered from Soda Lake beginning in the early 1900s.  Brine was pumped into shallow ponds and concentrated by solar evaporation.  Salts were then collected and refined on site.  A refining plant initially was located on the southwest shore of the lake.  In the late 1930s the refining plant was moved north, across the narrow neck on the east end of the lake.  Sodium sulphate is used in the manufacture of detergent, kraft paper, textiles and glass.  Some remnants of these historic operations is evident today. 

Despite this harsh environment, plant and animal species are well adapted to this alkali setting.  Birds and insects thrive in the shrubs that surround the lake and when conditions are right, numerous wildflowers bloom in the fields.  The lake itself is important to migratory birds.  During the winter months the lake may fill with water turning it into a roosting and feeding place for many migratory bird species such as sandhill cranes, American avocets, black-necked stilts and long-billed curlews.

BOARDWALK

Here we are at the boardwalk.  During the winter, Soda Lake may have enough water to be a shallow lake.  The depth of the water varies depending on the amount of rainfall, but averages between 1-3 feet.  In one really wet year the water level reached all the way up to Soda Lake Road at the base of the Overlook Hill.

In the dry months, water lies just below the salt crust.  Be careful if you walk out there, because you may break through the crust and sink into the mud.  We prefer that you stay on the Boardwalk.

The plant community that surrounds the lake is very rare.  Plants in this community have adapted to the high levels of salt.  The dominant shrub next to the edge of the lake is called Iodine Bush.  The next dominant shrub is spiny saltbush.  Both of these plants have special features that allow them to survive in the presence of so much salt.  Often in the sunlight you can see the salt sparkling on the leaves.

If you are here when there is water on the lake, look out to see if you can spot any of the the migratory birds.  Look close.  One of the birds that you might see is the sandhill crane.  They are most often seen and heard, early in the morning leaving the lake and in the evening returning.  They use the lake as a roosting place.  This protects them from predators such as coyotes.  During the day they go out to feed.  Historically they used to feed in the adjacent farming fields.  There are still some areas being farmed northwest of the monument that the cranes use to feed in.  If there is no water on the lake the birds will not stay on the monument but will travel to other areas such as Pixley and Kern National Wildlife Refuges in the San Joaquin Valley.  If you do not see cranes, look for other birds that may be swimming in the lake or foraging in the plants nearby.

Now, instead of looking across the lake, try looking closely down into the water.  You may see little, feathery looking things swimming in the lake.  These are most likely tiny brine shrimp or artemia that inhabit the lake when it has water.  Measuring only 8-10 mm, bring shrimp can live in water that has up to five times the concentration of salts that sea water has!  They serve as a food source for some of the birds that visit the lake.  

The Carrizo is distinguished for its world-class fossil assemblages (paleontology) and well exposed rock outcrops (stratigraphy).

Several rock formations were first recognized and defined within the Carrizo.  Which include:  the Paso Robles, Caliente and Morales Formations.

The Fort Tejon earthquake of 1857, with a magnitude over 8.0, was centered in the Carrizo and is probably the strongest earthquake to hit California in historic time. Surface ruptures extended 200 miles and offsets of 30 feet occurred within the Carrizo. Future seismic activity within the Carrizo is highly likely.

Research has been conducted on geological and paleontological aspects of the Carrizo since the 1906 San Francisco earthquake. Recent geophysical investigations measuring natural electrical current present at the earth's surface have been particularly successful due to the Carrizo’s isolation from population centers and lack of electrical interference.

Well, that’s our last stop on our tour.  From here you can return to Soda Lake Road via Simmler Road or you can continue your adventures exploring the rest of the monument.