East of Napa, the Skyline Wilderness Park spreads over two rolling mountains and has a range winding trails totaling 18 miles. A good starter route begins with a 600 feet vertical climb up old Lake Marie Road for 2.5 miles up to the lake. Then follow the trail counter-clockwise around the lake. Continue up the Skyline Trail to the valley overlook and continue on for the 4.5 mile rolling descent back. More? Try ascending Sugarloaf Mountain via the Rimrock Trail over 1200 vertical.
To reach the hiking trailhead from Napa on SR29, exit onto Imola Avenue heading east to its end.
Overall, Skyline Park is the 46th most popular hiking trail of all 88 hikes in California.