This is the longest possible loop on Rancho San Vicente and Calero (~9.5 miles). The trails are a mix of fire roads and wide singletrack. There are no technical sections, and the climbs are very gentle, which makes it a good place to bring beginners. There are nice views of the Calero Reservoir on the first half of the trail.
While the park has a surprising amount of tree coverage (for parks in this region), the southernmost trails (inside Calero) can get pretty hot, so bring plenty of water when riding during the hot months of the year. Also, keep in mind that not all trails in Calero County Park are bike legal! Consult the park map for up-to-date information.
Rancho San Vicente opened to the public in March of 2018. The park shares trails with the larger Calero County Park, for a total of 9.5 miles of trails. The trails are about 50% fire road and 50% "wide" singletrack (which will get weathered down over time and become narrower). All of the climbs on this loop are gentle, and most people won't ever need to touch their granny gear. This is a nice, flowy ride for those days where stress is not desirable or when introducing someone to the sport.
The front side of the park has nice views of Calero Reservoir (from a somewhat unusual point of view). When riding back, make sure to stop at Lisa's Lookout for a quick rest.
Rancho San Vicente connects to Rancho Canãda del Oro via the Cottle Trail
(get ready for the typical Bay area fire road climbs if you go that way.) It is also possible to connect to Almaden Quicksilver (via one mile on paved Almaden Road) or Santa Teresa County Park (via one mile on Fortini Road).