"At the trailhead there is a sign that reads: WARNING: BEWARE OF RATTLESNAKES, WILD PIGS, POISON OAK, AND TICKS. (I suggest wearing long pants to avoid poison oak and thistles.) This ride also contains an abundance of narrow singletrack. The first portion involves a long climb to the top of a ridge, over a mixture of smooth and rocky singletrack. Intervening downhill sections contain challenging sharp turns. The descent from the ridge to the inlet of Lake Marie is steep. The Chaparral Trail on the far side of Lake Marie contains a very steep and rocky climb. The descent from the lake is also very steep with sharp switchbacks, rock gardens, and roots. The last portion of the ride contains several challenging technical maneuvers down rocky chutes, followed by log water bars around corners that can become quite slippery in wet weather. Variety is the theme of this ride, in terms of both ecosystems and terrain. The result is a feeling of having spent a wonderful few hours in nature, and of accomplishment after having successfully accomplished some of the technical challenges. Highlights: Narrow singletrack, views of Napa Valley and the entire north bay area, wildflowers in spring and early summer, challenging technical uphill and downhill sections, lakes, rock gardens, bay forests, grassy knolls, manzanita groves. No motorized vehicles are allowed on the singletrack."