Visiting Vernal Pools

People of Sacramento County!

Did you know our very own Central Valley is home to one of nature’s brightest, rarest treasures? There is a magical flood-and-drought cycle that harbors strong, highly-adapted organisms right in our backyard! Come visit the vernal pools of Mather Field and experience the magic for yourself. 


Depending on the season of your visit, you will make different discoveries. In summer and fall the prairie’s clay soil hardens and cracks. This is the dry phase of the vernal pool ecosystem. Eggs, cysts and seeds lie buried on or under the surface waiting for their moment to hatch when the rains return. Out in the field you might find coyote scat with clues of what he ate inside. Snakes native to California like the Yellow-bellied Racer or the Common Garter Snake sometimes slither by. It is important to watch where you are stepping for you might destroy a home or clues to who is where! 


Winter rain welcomes the wet phase. This is the most active phase of the vernal pool grassland. There are millions of tiny swimming organisms to discover in the pools once they make their appearance. These tiny organisms, including the endangered fairy shrimp, are the basis of the prairie’s food web. Larger critters like the Pacific Chorus Frog and the Great Blue Heron feed off smaller life in the pools. Red-Tailed Hawks and Coyotes, some of the top predators, are also on the prowl for food. If you watch carefully, above and below you, you are bound to witness part of the food web in action!


As water from the pools evaporates, rare flowers begin to show themselves. This is the flower phase. Most of these flowers are only able to grow in vernal pools. Each pool has different conditions that harbor different combinations of flowers. Paying close attention to the differences can be quite remarkable. Often times the flowers grow in colorful rings because of the specific conditions they prefer. Make sure you leave the flowers safe in their habitat and respect their unique beauty without picking or trampling them. 


Here are three satellite images from Google Earth that depict the same vernal pool landscape at Mather Field at three different times of the year. Can you tell which image features this rare plant community in its dry, wet and flower phase?