A name from the powder-boom years

Long before it was a hiking backdrop, Powder Mill Creek powered industry. The California Powder Works was incorporated in 1861 by San Francisco businessmen desperate for blasting powder after the gold rush demand surged and the Civil War threatened to cut off Eastern supplies. In 1862 they bought a flat beside the San Lorenzo River, three miles upstream of the city of Santa Cruz, drawn by water power, timber for charcoal and kegs, transport and a measure of seclusion.↗↗

By 1863 the company had raised twenty-five buildings in what was called Powder Mill Canyon, later expanding to some seventy-five structures, including twenty-one powder mills. Water from a dam on the river, channeled through a 1,200-foot tunnel and a web of flumes, drove the mill machinery and purified crude saltpeter shipped from Chile. For half a century it was the biggest explosives producer west of the Mississippi, and the creek that fed it gave the whole site its name.↗↗↗

The industry was dangerous. An 1898 explosion in the smokeless-powder plant killed thirteen men and injured twenty-five, shattering windows in Santa Cruz below. DuPont took control in 1903, the Santa Cruz operations were shut down in 1914, and the mills were dismantled. In 1924 the land was sold to a Masonic group that developed it into the private residential community of Paradise Park. The creek's story survives in its name, in a few scattered remnants, and in the timber covered bridge assembled in 1872 to carry the works' narrow-gauge rail spur across the river.

Following the water on the trails

Powder Mill Creek rises at around 600 feet near the park's campgrounds and falls toward the river, its course paralleling Graham Hill Road and the park's trail spine. The most direct way to be near the water is the Powder Mill Trail, a roughly 0.7-mile hilly walk through mixed woodland that drops from the ridge country toward the valley; bikes are not allowed on it, though dogs are welcome on leash.↗↗

Wider and gentler, Powder Mill Road (about a mile) and the long, spring-fed Pipeline Road climb through second-growth redwoods and are open to cyclists. Where the creek meets the San Lorenzo you get a glimpse of the world the powder workers knew: the river trail below, with its lush streamside growth and the steelhead and waterfowl of the big river it feeds.↗↗

The redwood park around it

The creek threads through Henry Cowell Redwoods State Park, most famous for its 40-acre grove of old-growth coast redwoods reached by a flat, wheelchair-friendly 0.8-mile loop. The largest tree stands around 277 feet and is roughly 1,500 years old; explorer John C. Frémont camped among these giants, and a 1900 visit by photographer Andrew P. Hill helped spark California's redwood preservation movement.↗↗

Climb above the grove and the landscape flips into the rare Santa Cruz Sandhills, an ecosystem of ancient marine deposits where ponderosa pines stand at improbable low elevation and endemic plants and the endangered Santa Cruz kangaroo rat persist. The Pine Trail and the Observation Deck, the park's high point at 805 feet, reward the effort with views sweeping out to Monterey Bay and the Santa Cruz Mountains.↗↗

For a wider view of the era the creek belongs to, Roaring Camp Railroad sits right next to the park, running heritage steam-train excursions through the redwood forest on the old lumber-railway grades. It adds the living sound of the timber and powder country that once crowded this valley.↗

Seeing the historic covered bridge

The most evocative relic tied to the creek is the California Powder Works Bridge, a Smith-truss covered timber bridge built in 1872 and listed on the National Register of Historic Places—the longest single-span bridge in the county when it went up. It spans the San Lorenzo near the creek's mouth, in the heart of the old works.↗↗

One important caveat for visitors: the bridge lies inside the gated Paradise Park residential community, so it is not an open public attraction you can simply walk up to. Treat it as the historical reason the creek is named what it is, and keep the public state-park trails as your route for getting into the same landscape the powder works once commanded.↗↗