A RIVER RUNS THROUGH IT

The San Lorenzo River winds twenty-nine miles from its headwaters 2,500’ feet in the Santa Cruz Mountains down to Monterey Bay. According to park naturalists the San Lorenzo River and movement on the Ben Lomond Fault are the primary forces that shaped the landscape of Henry Cowell Redwoods State Park.

“The northern part of the park is composed of soft sandstone and mudstone, with fossil evidence that it was once a shallow inland sea, including sand dollars and shark teeth. The southern portion of the park consists of harder granite and schist formed from magma. These geologic factors determine the vast diversity of flora and fauna that inhabit the park.”

In the 19^th century the San Lorenzo River drew many tourists because it was considered one of the best steelhead trout and coho salmon regions in Central California.  

Scott Peden Collection

Early visitors to Big Trees Grove would turn off the road to Felton at the Toll House, then meander down to the San Lorenzo River. There they forded the shallow riverbed to reach the grove’s original entrance [near the Giant – the midway point of today’s Redwood Loop Trail]. The area along the edge of the river which is shaded by laurels, white alders and towering sycamores was once known as Idlewild Glade. Visitors pass through this historic glade when walking today’s River Trail from the Group Picnic Area.

In 1882 a group of Pennsylvania visitors vividly described their journey to the grove along this route:

“The road led through the most romantic scenery; precipices on one side and flower-covered rocks on the other, the blue heliotrope the size of trees, the bright pink valerian and the wild azaleas making a wilderness of flowers. Presently the horses sped down a deep declivity and entered the San Lorenzo river through whose crimson waters dyed by the dust of the Redwood forests we traveled for some distance and finally entered the primeval forest. There the sweet odors of the bay trees, the deep silence and the overpowering size of the trees for a time stilled the gay laugh and produced a solemn calm.”

The Pennsylvania visitors’ description of the “crimson waters,” of the river likely had a much darker meaning. The San Lorenzo River wound through one of California’s major logging regions. By the late 1860s the San Lorenzo Valley supported twenty-two lumber mills with an annual capacity of eleven million board feet of lumber. In 1872 the California State Legislature received a report on the fisheries of the coast rivers between Spanishtown and Pescadero by Captain Wakeman. In the Purissima he observed that “[t]he sawdust and blocks of the redwood are thrown into the streams, which turns the water to a dark red, and, in some places, to an inky black; in other places to a purple [evidently from the redwood bark's tanic acid].” 

Apparently, the San Lorenzo River was suffering the same fate. Wakeman concluded “that the redwood sawdust poisons the water, and unless some other method be adopted to get rid of it … there will not be a breed of trout left in a few years. Where thousands were taken daily (thirteen hundred by one person), now scarely a trout can be seen. If there are laws to protect them I can see no good reason for not enforcing them …”

Over the past century, pollution, over-fishing, and construction of dams all drastically reduced the river’s fisheries. Though today trout are listed as threatened and the coho salmon are endangered, major restoration efforts are now underway by a myriad of conservation groups and volunteers. Hopefully, through the efforts of all of us, the future of the San Lorenzo River can be described in the same manner as it was in the past.

For since the world began,
And San Lorenzo ran,
Was never scene so lovely
Displayed to mortal man.

        — Daily Alta California, July 5, 1880

Sources: “Our Occidental Borders,” by E.S. Blanden in the Pittsburgh Post Gazette, July 5, 1882; Valley of Redwoods – A Guide to Henry Cowell Redwoods State Park by Robert W. Piwarzyk and Michael L. Miller, 2006; Appendix to Journals of Senate and Assembly of the Nineteenth Session of the Legislature of the State of California, Volume II, Sacramento, 1872; San Lorenzo River - River Facts,” Coastal Watershed Council, https://coastal-watershed.org/san-lorenzo-river/about-the-river/; California State Parks, Henry Cowell Redwoods State Park, Natural History, https://www.parks.ca.gov/?page_id=28583; “The San Lorenzo Valley Flume Chronicle,” by Lisa Robinson in Redwood Logging and Conservation in the Santa Cruz Mountains: A Split History, 2014.