Vernal Pool

My colleague Craig and I hadnt taken a hike since our search for the source of Stenner Creek last July. Ian was still on recess from Nursery School. So last Friday afternoon the three of us drove in Ruby RAV up TV Tower Road on West Cuesta Ridge to make our way back by foot down to Cal Poly and home.

From where we parked the unearned views of the Chorro Valley, the Morros, and the Pacific were splendid,
though marred by the foreground presence of broken glass and several glistening piles of offal that looked like recently dumped deer guts. We passed by them hastily and clambered down the steep lip of the ridge top. I told Craig about the time I'd taken this route with my previous hiking buddy, Doug, who died six years ago of lung cancer. People were shooting old television sets in this sacrosanct spot, and after we passed them and rounded a curve in the fireroad, a spent bullet came over the bluff behind us and hit the back of his leg, tearing his pants, but not breaking the skin.

Passing from Los Padres National Forest Land through a gate onto Cal Poly Land, we took a trail I'd never been on heading from the ridgeline toward the watercourse containing the immense oak tree I'd slept under many times, which I wanted to show Ian. But Craig led the way and swerved south across a broad swath of grassland toward the top of Poly Canyon.

At the shoulder line of the hill, we saw the landscape below center itself around a small blue mirror set in a shallow green hollow. I recognized it as a vernal pool. I'd never seen one on Cal Poly land before, and from this vantage it looked mysterious and powerful--a place where you might find a magical sword or a frog prince.


The name of this geological feature had always appealed to me, and I had learned something about it in connection with struggles to preserve the small number that had remained in the Central Valley after 95% were destroyed by agriculture and development. The pools are formed, as are springs, where rainwater percolating downward meets an impermeable clay surface and finds no channel through which to run off. They provide habitat for rare species of plants, most of them native, endemic and endangered. Because the pools emerge during the wet season and dry up during summer and fall, introduced species that havent evolved locally to adapt to these conditions cant thrive here and outcompete the natives. Many of them produce dramatic displays of flowers during the spring, after the water disappears but before the area dries out.

Rare, ephemeral, and productive--we had come upon treasure. Ian was getting tired after a long day with no nap so Craig carried him on his shoulders while I lingered behind relishing the vision of the two of them crossing the gently curving greensward and closing in on that pure eye staring up at the firmament.

I wanted to slow my own approach to the snail's pace at which I sometimes travel alone in this countryside, but the afternoon was getting on. The closer I came, the greener and thicker the pasture, the more intense the reflections of red basalt outcrops and sky in the low angling light.

The uphill margent of the pool had a hard edge. The lower side gradually merged with the spongy shore, recalling a descriptive passage I liked to read aloud in class from Shakespeare's The Tempest:

Thy turfy mountains, where live nibbling sheep,
And flat meads thatch'd with stover, them to keep;
Thy banks with pioned and twilled brims,
Which spongy April at thy hest betrims,
To make cold nymphs chaste crowns.

I wanted to strip, leap in the water and drink my fill, but fear of a cold and of giardia held me back. I wanted to be here alone with a sleeping bag and stay the night.


The knifebladelike plants on the lower side of the pool grew half in and half out of the water. Were these some of those rare endemics? A few days later I emailed a colleague who teaches botany with this picture. He said, "There is no way to be sure, but I think it looks like one of the 'iris-leaved' rushes such as Juncus phaeocephalus.... a relatively common plant of periodically wet meadows."

I tried today, MLK's birthday, to get back and check the changes in this pool after a weeklong dry period and the more recent rain. I arranged a hike with Ian and another four year old, Francis, his two year old brother, and their two parents, Tom and Jennie. We started at Serrano ranch but only got as far as Serrano station, where we picnicked and turned back. Instead of the pool we saw the crane train repairing the tracks and climbed embankments and haystacks.