When you think of the Central Valley you probably don’t think about volcanoes. But just outside of Fresno there’s unmistakable evidence of how an ancient volcano helped shape the landscape we know today. On this edition of KVPR’s Central Valley Roots – the story of the tabletop mountains in the foothills near Millerton Lake.
In a landscape full of grass covered foothills and jagged Sierra peaks, the flat-topped mountains near the San Joaquin River northeast of Fresno stand out. A little over 9 million years ago, a volcano near present day Mammoth Mountain erupted, sending lava into the channel of the ancient San Joaquin River.
Over millions of years, the rest of the landscape eroded away, but the volcanic tabletops remained. In many cases, river rocks can be found beneath the volcanic surface of the tables. 33 remnants of the lava flow remain today, with names like San Joaquin Butte, Kennedy Table and Pincushion Peak.
Some of the land is accessible to the public from the San Joaquin River Trail, and the Bureau of Land Management's San Joaquin River Gorge Recreation Area. The Sierra Foothill Conservancy preserves and manages other parts of the ancient plateau, including the Ruth McKenzie Table Mountain Preserve. This 3,000 acre working cattle ranch holds special hikes and events throughout the year that give the public a glimpse of one of the valley’s most incredible natural landscapes.
