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Written by: Angela De Palma-Dow

Published: 28 April 2024

Dear Lady of the Lake,

How did Clear Lake get its name? Was the Lake clear at one point? Will it be clear again?

Thank you for your column!

— Susan C, Seeking clarity about Clear Lake

Hello Susan,

Thanks for asking those very interesting questions. I actually get asked this quite a bit, it's a very popular quandary and I wish there was a simple answer!

I have done some extensive research into both Lake County and Napa County histories, as Lake County was a part of Napa County until it was designated as its own county in 1861. So until 1861, Clear Lake was actually a lake within Napa County.

According to research recorded in 1960 by Lake County historian Henry K. Mauldin, the origins of the vernacular “Clear Lake” are unknown (Book 1, pg 12). Both Mauldin and the United States Geological Survey Geographic Names Information System list previous names and variants, as reported by European settlers, hunters, or explorers, to include “Big Lake,” “Lagoona,” “Laguna,” “Laguna Grande” and “Laguna Grande de Napa”, “Kah Shoh.”

Academic studies, such as a 1950 thesis written by the geographer Fredrick J. Simoons indicated that European settlements started as early as 1840, with agricultural settlements starting in 1854, with a dramatic increase in the basin population occurring around 1866-1870. References within this time frame do refer to the lake as “Clear Lake”, so we can surmise that this was the time period where the current lake name originated.

While Clear Lake is the name the lake goes by now, let’s remember that the indigenous residents that lived here for an estimated 20,000 years before european influences and settlements arrived, and these native peoples had their own name and references to Clear Lake.

Clear Lake has been known as Ka-ba-tin [Xa’Batin] or Hok-has-ha, meaning “Big Water'' in some native Pomo languages. Be aware that pronunciation, names and labels vary by region and dialect through space and time.

For example, the meaning and pronunciation of Kabatin vs Xa’Batin: Ka means spider, but the sound for Xa is more of a sound for “H”, think of the sound when you say the name “Howard.” Some people associate the sound with a “K”, which in many instances wrote the name as Kabatin which would actually mean big spider. A good way to sum it up is as follows: Xa = Water, Ka=Spider, Batin=Big, Giant or Tall.

Additionally, I offer this strong Note on the general use of “Pomo” as describing the collective native peoples within Lake County, that this term generally disregards the regional variation among tribes and groups.

So, while the federal government and linguists recognize “Pomo” (or variations such as “Kula Kai Pomo,” “Ballo Kai Pomo”) as the descriptor for the local Indigenous native peoples, some local tribes, have historically self-identified, linguistically, as “Hinthil,” “Gowk Xabatin” or “Kulanapo,” “Kulanapan” or other terms that originated from the distinct tribes, villages or regional collection of peoples within different areas of the Clear Lake basin.

Clear Lake is not clear and probably never was

So now that we have some history for the origins of the name “Clear Lake,” let’s address your second and third question Susan, regarding the clarity of the Lake.

In the majority of the warm summer and fall months, Clear Lake’s water column usually develops an opaque, green color, and in some areas a thick mat of plants or cyanobacteria will develop, sitting (and sometimes stinking!) in the sun. This phenomena definitely encourages some confusion when a lake is named “Clear.”

However, it does not appear that cyanobacteria, also referred to as blue-green algae, are a recent development in Clear Lake. Since water monitoring wasn’t occurring prior to the mid 20th century, the only way to gather information about the lake’s historical water quality, and clarity, is through the lake's sediment.

Sediment cores collected from the bottom of Clear Lake by the United States Geological Survey (USGS) indicate Clear Lake has been nutrient-rich (eutrophic) with high algal populations since the last ice age, which ended approximately 10,000 years ago.

Whatever was growing or floating in the water would end up sinking to the bottom, contributing to the composition of the cores.The sediments act as a time capsule, sequentially exposing the conditions of the lake from the past, through time.

Over the past 50 years there have been several cores studies, and some of the core studies reflect that last 300 years and some of the larger cores capture up to 175,000 years of in-lake information.

The algae pollen cores measured about 2.5 meters in length, and contained information on pollen, nutrients, and metals expanding 300 years from present day (of the 1980s, to be exact).

Generally, what these core contents reveal is that Clear Lake has historically always been green, full of life, and probably not too clear.

To learn more, you can view the Algae Pollen Graph, extracted from the core study, which shows the change in algae pollen over time from a core extracted from the Upper Arm.

Historic reporting to Congress about Clear Lake from 1870s

Livingston Stone, a fisheries “expert” and biologist, visited Lake County in 1873 and reported to the U.S. Congress that Clear Lake had significant algal populations at the time. In addition to a detailed month-by-month account of fish in the lake and streams, Stone characterized the eutrophic, nutrient-rich and productive nature of Clear Lake, describing surface blooms and scums during the warmest months of the year.

And excerpt from his written passage is quoted below:

“It is a singular fact, illustrating the inaptness with which names are often given to natural objects, that the water of Clear Lake is never clear. It is so-cloudy, to use a mild word, that you cannot see three feet below the surface. The color of the water is a yellowish brown, varying indefinitely with the varying light. The water has an earthy taste, like swamp-water, and is suggestive of moss and water-plants. In fact, the bottom of the lake, except in deep places, is covered with a deep, dense moss, which sometimes rises to the surface, and often to such an extent in summer as to seriously obstruct the passage of boats through the water.”

During Stone’s seasonal accounts, he describes the water conditions in September:

“The water this month is in its worst condition. It is full of the frothy product of the soda-springs. A green scum covers a large part of the surface, and it is not only uncleanly to look at, but unfit to drink; and yet, strangely enough, this lake, which one would think uninhabitable by fish, fairly teems and swarms with them.”

It would seem, that even in the 1870s, that Clear Lake was not Clear in the summer and fall months, and even then, as now, it seems fitting that the reference to “clarity” does not apply to Clear Lake waters.

You can read the full text of Stone’s Clear Lake, and other California accounts, here: https://penbay.org/cof/cof_1873-1875_xx.pdf or at the Lake County Water Resources website here.

Remember that water clarity in lakes and reservoirs is also influenced by the organic materials floating in the water, the total depth, the temperature, and the composition and content of the surrounding landscape.

More information about what makes Clear Lake colors change throughout the year, from blue, to brown, to green, can be found in my previous column, (February 2022) Brown Water Got you down?

Clear – Air – of Clear Lake

Many newspaper articles and local legends state that Clear Lake was named after the air quality of the valley in which its basin is formed, and not given to the Lake to describe its water quality.

However, in my research I could not find this original reference, only generalized statements within gray literature, without reference to the original source or sources.

This is interesting when you consider how lake names are created across the country. According to a study conducted by Continental Limnology research group, 83% of all the lakes in the US are unnamed, with about 80% of those lakes being smaller than 4 hectares (9.9 acres). Of the 83,000 lakes that did have associated names, the majority of the lakes were named to reflect people’s everyday lives, to inspire creativity, and to incorporate regional indigenous languages.

The most common lake name in the U.S. is “Mud.”

Lake names also vary regionally, with co-dominant terms being given to lakes based on region within the US. For example, besides the term “lake,” Arizona, New Mexico and Texas use the term “tank” to refer to lakes or reservoirs, while the Eastern seaboard predominantly refers to lakes as “ponds.” Here in California? We use both Lake and Reservoir pretty consistently throughout the state. 

Regardless, Lake County, and especially the valley of which Clear Lake is located, has some of the best air quality in the state, which makes a strong argument for the name bestowed upon the lake.

According to the National Institute of Health Air Pollution Tables, Lake County ranks the best in air quality when comparing the amounts of particulate matter in the air (measured by 2.5 micrograms per liter). In 2019, Lake County recorded the lowest amount at 3.1 mg/L PM2.5 compared to the state average of 7.1 mg/L PM2.5.

And if you want to track current air quality, you can use OpenAir.

IQ Air provided current air quality and pollution indices, along with current wind and wildfire and smoke conditions. <>

I hope this column helped to “clear” the air about how the name Clear came and didn’t come to be. Susan, I also hope that you will join me in being slightly thankful that our beautiful lake didn’t end up being called Mud Lake, am I right?

Sincerely,

Lady of the Lake

Angela De Palma-Dow is a limnologist (limnology = study of fresh inland waters) who lives and works in Lake County. Born in Northern California, she has a Master of Science from Michigan State University. She is a Certified Lake Manager from the North American Lake Management Society, or NALMS, and she is the current president/chair of the California chapter of the Society for Freshwater Science. She can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..

If you would like to talk to the Lady of the Lake in person, you can stop by her booth at the Big Valley Small Farms Tour, Saturday, May 11, at Ripe Choice Farm, 10 a.m. to 3 p.m.