Both these parks have picnic areas and admission to one includes the other. Bale Grist Mill State Historic Park features a 36ft-high water-powered mill wheel dating to 1846 – the largest still operating in North America; Saturdays and Sundays (and sometimes Fridays and Mondays) from 10am to 4pm, it grinds flour. A mile-long trail leads to adjacent Bothe-Napa Valley State Park , where there’s a swimming pool ($5), and camping , plus hiking through redwood groves.
If you're two or more adults, go first to Bothe and pay $8, instead of the per-head charge at Bale Grist. The mill and both parks are on Hwy 29/128, midway between St Helena and Calistoga. In early October, look for living-history festival Old Mill Days.
