From the air, Trione-Annadel State Park — affectionately just “Annadel” to many — stands like a tall, 5-mile- long island, floating between the flat valleys of Santa Rosa on the west and Sonoma to the east. And like an island adrift in a sea of development, the massif carries a trove of lost natural treasures. Despite Annadel’s 40 miles of official trails, many of its treasures lie hidden from casual view: Few know, for example, that Annadel is home to four types of blooming orchids.
That low profile is a mixed blessing to the small team entrusted with its care. Concealed in the wild, Annadel’s unique features are spared the damage that often comes with human contact. But if they’re kept secret, the public may not support the long-term efforts required to protect them.
While the park today is primarily a recreation magnet, the landscape itself has stories to tell, and the natural history of Annadel is a fascinating tour through time and change.
History of wildfires
October’s firestorm was not the first time flames have swept the Annadel landscape, and how often the fires return is an important question. To find out, Mark Finney, a young Berkeley researcher, hit on the idea of examining ancient redwood stumps in Annadel, looking for burn scars amid the tree rings, which he could then count to track time between fires. What he found was unexpected. Before the mid-1800s, there were fires every six to 23 years on average, and as often as every two years.
That was puzzling, because natural fire starts, such as lightning strikes, are very rare here. The frequent fires suggested a different cause: That they’d been set by humans. And indeed, the native people who came to live in Sonoma County at least 8,000 years ago — the Wappo, the Southern Pomo and Coast Miwok — were skilled in using fires to manage the wild resources here.
The first people established walking trails throughout the region, including the land now enclosed in the park’s boundaries. Ancient camps mark their presence along today’s Canyon and Marsh trails, which were well-trod routes for thousands of years: They provide the easiest passage for those crossing between the Santa Rosa and Sonoma Valleys. Kate Green, associate archeologist for the State Parks District that includes Annadel, believes from historic understanding and dated evidence that native groups lived mainly in the rich valleys on either side of what today is the park, but visited its high slopes and meadows for the unique resources they found inside.
Using fire to manage the landscape has a number of benefits. First, frequent fires don’t burn as hot or destructively. The ash creates luxurious growth in grasses that attract game, and fire knocks down pests like ticks, while clearing openings in the brush and understory, making movement and access to resources like fallen acorns easier. Fire also dramatically stimulates the growth of certain fire-adapted California species, like the native soap plant. Its sap was used as a lathering shampoo, bulbs were roasted as food and fibrous skins were excellent for scrubbing.
Today, in the burned regions of Annadel, last year’s fires have created a sudden explosion of soap plant, recognizable by its rosette of long, unusual wavy green leaves. While they’re no longer harvested by the descendants of the first people who lived in Sonoma County, they’re a reminder of the respect and old ways of stewardship with nature.