WINE COUNTRY’S WILDER SIDE.

Out at Moore Creek Park, you learn to keep an eye to the sky. You never know when a bald eagle can fly right overhead and take you by surprise.

A mated pair of eagles tend a nest in the woods overlooking adjacent Lake Hennessey.

Out in a kayak on the lake, homing in on the bass in a cove, you can be shocked out of your bubble when a bald eagle plucks a fish off the lake. On a shoreline hike, you can be taking in a sweeping view of the lake, when one of the eagles emerges overhead. An eagle in direct flight is traveling, a hovering eagle is on the hunt, and a diving eagle — well, you and the eagle might have just hit the jackpot.

The best chance for such an encounter is at dusk on a spring day, when the fish leave the cold water for the warming surface thermals, and become vulnerable to the predator in chief in the sky. Moore Creek Park and Lake Hennessey are 30 minutes northeast of Napa, yet get overlooked because it is outside the wind corridor in the valleys. Some call Hennessey Conn Dam, but by any name, it is a pretty 850-acre lake ideal for kayaks and low-speed fishing boats, with a 10-horsepower limit on motors. Moore Creek Park borders the lake with several excellent hikes and work to add more.

This past week, in a temporary action, Napa County closed the boat launch at Lake Hennessey due to high-water conditions. The lake not only topped off, but also roared over the spillway, and at the plunge pool, sent a rocketing plume of water into the air and into Conn Creek. It has been so spectacular that water watching might be declared a new spectator sport.

Officials would not say when the boat ramp would be reopened, but the long-term forecast predicts diminishing rain totals compared with the first three weeks of February. That would allow the lake to stabilize and reopen. In addition, temperatures routinely rise into the mid- to high 60s in March. As spring arrives, the surrounding oak woodlands can glow electric green, and as the lake settles, it clears and transforms into an emerald gem.

Here’s how to make the trip work.

Moore Creek Park

What started as a good idea for a park has become living proof of how a public-private partnership can flourish. It’s been five years since Moore Creek Park opened, and volunteers have spent more than 10,000 hours building trails. With oversight from Napa County, parking and access is free, and trails are open to hiking, leashed dogs and, in some areas, mountain biking and horseback riding.

It is one of the few parks in Northern California where volunteers with county oversight continue to develop and build new trails, and that makes it a model for many park districts.

The park rises up from Lake Hennessey and is managed as two units, the Hennessey Unit and the Moore Creek Unit. When you park at the main lot (not the boat ramp), the Hennessey Unit is to the south, and the Moore Creek Unit is to the north.

At the Hennessey Unit, there is a 6.2-mile loop trail, best done counterclockwise, which provides a panorama over and across the lake. Start at the trailhead for the Chiles Creek Trail and walk a mile to the junction for the Alta Hennessey Trail. Here you turn right, where the trail then rises up to the ridge for occasional sweeping views of the lake. The trail then descends to the lake’s shore. Take the Shoreline Trail, which is routed above the lake and connects with Chiles Creek Trail and back to the parking lot.

As spring takes hold, this is a pretty walk through a mix of oak and madrone on the sun-exposed foothills, and pine and firs in the shaded ravines. With such heavy rains in the past month, many are predicting a big wildflower season in the Napa County foothills, probably starting in midMarch and peaking in mid- April.

In the future, new trails are planned for the Moore Creek Unit. This is located to the north of the main parking area. It consists primarily of riparian woodlands that extend upstream along Moore Creek for several miles. In the future, volunteers and Napa County plan to complete the Dryfoot