Clear Lake                     

At the heart of the paradise that is Lake County lays the Clear Lake basin.  Five superlatives paint word pictures of Clear Lake.

Largest:  Clear lake is the largest natural freshwater lake in California, with 64 square miles of surface area and measuring 19 miles long and 8 miles across at its widest.  There are over 100 miles of shoreline.  Average depth is 28 feet.  Water temperature averages 61° and varies from 40° in the winter to 75° in the summer.

Most Productive:  The lake may hold more fish per acre than any other lake in the country.  The 100 miles of shoreline offer ideal habitat for fish.  Downed trees, tules, water grasses and piers provide shelter for sport fish such as bass, crappie, bluegill and catfish. Native fish include blackfish, Sacramento perch, tule perch and hitch.  Silverside minnows and threadfin shade are also food sources for the sport fish.

Best Fishing:  The lake provides the best bass fishing in the West.  Bass fishermen can be spotted at dawn any day of the year.  Over 20 bass tournaments are conducted annually, with frequent additional regional club events. 

Catfishing draws increasing numbers of enthusiasts, particularly to the annual Catfish Derbies held at the southeast arm of Clear Lake.

Oldest:  Clear Lake is probably the oldest lake in North America.  The basin that would become Clear Lake lifted above sea level perhaps 50 million years ago, the result of a collision of the Pacific and North American crustal plates.

            Geologists Norm Lehrman talks about this “geologically live” area: “Things are moving and changing all the time.  Activity along the San Andreas and related faults reached this area about 3 million years ago, creating a plumbing system which extends deep into the earth.  Through these fractures, magmas rose, and the Clear Lake volcanic field exploded into life.”

Most Unusual:  Most lakes this old would be grassland today.  Clear Lake began some 2.5 million years ago as a series of small oxbow lakes scattered along ancestral Cache Creek.  Horses, camels, deer, ground sloths and even Mammoths grazed along the shores.  With time the valley deepened and a larger lake covered the area.

            Ancient lake sediments exposed in Big Valley reveal 400,000-year-old fish fossils consistent with the native fish population of modern Clear Lake.

            Down in the lakebed, vent holes emitting vigorous bubbles of carbonated soda water are visible at the water’s surface.  Divers report that the springs in Soda Bay emerge from cylindrical shafts up to feet in diameter and over 100 feet deep.

            The larger holes host ecosystems which serve as nursery colonies for millions of juvenile catfish, attracted by the protection afforded by the caves and abundant food supplies.  Food is plentiful because the upward-jetting springs cause an inflow of lake water down the vent walls, sweeping insects larvae and other debris into the vents.