Eggs made Petaluma famous. In the early twentieth century this town in southern Sonoma County, an hour north of San Francisco, called itself the egg basket of the world, thanks to hundreds of chicken farms around it and an incubator invented here that helped revolutionise poultry farming. Today the chickens are fewer, but the town still has a strong farming identity, with dairies, cheese makers and creameries in the hills around it.
Petaluma's downtown is a pleasure: a row of nineteenth-century iron-fronted buildings along the river, many of which survived the 1906 earthquake that wrecked so much of the region. Film directors love it for its period look, and scenes from American Graffiti and Peggy Sue Got Married were shot here. The Petaluma River, technically a tidal slough, winds through town toward San Pablo Bay, and the old riverfront warehouses now hold shops and restaurants.
As for swimming, the honest answer is that the ocean nearby is cold and rough, with big waves and strong currents, and the town's river is not for swimming. Dillon Beach, about forty minutes west, and the beaches around Tomales Bay are the closest places to get in the water, but the Pacific here rarely gets above the mid-teens Celsius, so it is a quick, brave plunge rather than a lazy swim. Many people settle for wading.
The real treat is the riding. West of Petaluma, roads such as the Point Reyes–Petaluma Road, Chileno Valley Road and the Bodega Highway wind through rolling grassland and dairy farms toward the coast. These are narrow, quiet roads with plenty of corners, short climbs and sweeping views of golden hills dotted with oaks and black-and-white cattle. The surface varies, and you will meet cyclists and slow farm traffic, but on a clear day it is wonderful riding.
Petaluma has everything you need, from fuel and motorcycle shops to excellent restaurants and cafes. On the way back south toward San Francisco, the 101 freeway gets crowded, especially on weekend evenings, so an early return or a slower route along the backroads through Nicasio and Lucas Valley makes a gentler end to the day.