Our mission: Find the headwaters of the Napa River, that hidden spot where pristine water bubbles up, beginning its 55-mile passage to San Pablo Bay.
Maps were not particularly helpful. The thin blue line marked “Napa River” peters out north of Calistoga, becoming a spider’s web of tiny streams, many without names.
We made the call to the Napa County Resource Conservation District. Jonathan Koehler, a senior biologist, answered the phone.
Our quest amused Koehler. Did we truly think the river could be traced to a bubbling spring?
Why not, we said. It would make for a good photo.
The Napa River definitely has its start on the slopes of Mount St. Helena, Koehler said, but good luck deciding exactly where.
Koehler preferred to think that the river began at the juncture of the first two named creeks. This would make the starting point north of Calistoga, where Kimball and Blossom creeks meet up, he said.
Others might identify the lower reaches of Garnett Creek, which drains the Palisades northeast of town, as the starting point, Koehler said. Garnett is probably the area’s most powerful stream.
We were not impressed with either location, so Koehler offered up yet another option. How about the highest, most northern spot in the Napa River’s watershed?
That was more like it.
If you want to find this ultimate source, then prepare to climb Mount St. Helena’s southern slope, Koehler said. In winter and spring, ephemeral streams trip over this weathered, rocky surface, eventually forming Kimball Canyon Creek.
We had better move fast, he said. These rivulets don’t flow year-around. If we wait until summer, “you might not be able to catch the headwater in action.”
This was troubling information. We might stumble around on treacherous terrain only to find that the unnamed headwater streams of the Napa River had quit for the year?
When pressed, Koehler suggested a more practical approach with higher odds for success.
Years ago the city of Calistoga dammed Kimball Canyon Creek for a reservoir, he said. The base of Kimball Dam is a convenient place to mark the start of the river’s run.
Earlier this month, on a sunny day following heavy rains, we hooked up with Jim Smith, a civil engineer in the Calistoga Public Works Department, who had offered to take us to the Napa River’s most commonly recognized starting point.
As the source of nearly half the city’s water, Kimball Canyon reservoir — four miles north of town, elevation 575 feet — is off-limits to the public.
The reservoir is dominated to the north by Mount St. Helena, elevation 4,342 feet. On the day of our visit, a light dusting of snow covered the mountain’s green, undulating summit.
We decided to dignify this thin veneer of white with a label worthy of the Sierra Nevada. That’s the Napa River snowpack, we said.
The photographer, J.L. Sousa, quickly took a picture. Our snowpack would melt by mid-day.
Fortunately, we had come at the wettest time of the year, Smith said. The reservoir had been overflowing down a concrete sluiceway for several months.
The creek below the dam was a raceway of noisy but non-threatening intensity. We drove across the fast-moving creek, then up a dirt road, through a forest of firs, cedars and madrone. Rounding a bend, we were greeted by a picture-perfect little lake, Kimball Reservoir.
An earthen dam, 300 feet long, 75 feet high, holds back the waters of Kimball Canyon Creek. The dam was built in 1939, then raised a decade later.
So this, a reservoir of stunning beauty, was the source of the Napa River. We had no idea that the Napa, which is a sluggish beast in its lower reaches, started so elegantly.
The reservoir was framed by abundant nature. There were no houses, no cattle, no vineyards. We could have been in the High Sierra.Because of recent heavy rains, the water was a murky brown, but it would change to blue-green for summer, Smith said.
Whipping out a calculator, Smith estimated that 374 gallons a second were flowing down the reservoir spillway. That’s how much water was seeping off the 2,000 acres of Mount St. Helena’s southern slope that comprise the Kimball Canyon watershed — most of it within Robert Louis Stevenson State Park.
If we came back in summer, it would be a different story, Smith said. The mountainside would be an arid brown. Flows into and out of the reservoir could be as little as three gallons a minute — less than a garden hose can deliver.
The happy stream we had crossed below the dam will dry up. Three gallons isn’t enough to maintain a puddle, Smith said. In summer and fall, the first couple of miles of the Napa River are in dry weather hibernation.
Things pick up at Tubbs Lane near Old Faithful Geyser. Even in summer, the Tubbs area is rich with springs. The Napa River begins to flow again, Smith said.
In downtown Calistoga, at Pioneer Park, the river has two personalities. In summer, it’s a shallow and slow-moving pool, a splash zone where children safely play.
In winter, after a heavy storm, torrential flows sweep through downtown Calistoga, scooping up anything that’s not tied down. Eight hours later, Calistoga’s debris is racing through downtown Napa on its way to the sea.
Bo Barrett has been living on the upper Napa River, north of Tubbs Lane, since the early 1970s. He’s part owner of two family wineries, Chateau Montelena and La Sirena, that have more than a mile of river frontage.
The river in springtime is a lovely thing, Barrett said. When water’s flowing, the occasional steelhead has been known to make it this far upstream.
Come June, the upper river’s personality undergoes a 180-degree makeover. Water evaporates, leaving a dry, rocky stream bed, Barrett said.
Even when the river is nothing more than rocks and dirt, it’s year-in, year-out contribution to the Napa Valley’s wine industry should not be minimized, Barrett said.
Viewed through the prism of geologic time, the river gets credit for washing down the alluvial soils that make the Napa Valley such a special place to grow premium wine grapes, Barrett said.
Barrett tags his winery e-mails with an old saying adapted to reflect his upper Napa River chauvinism: “At the top of the Napa Valley. Always drink upstream from the herd.”