Mountain biking was born in Marin, so it’s no surprise that miles of meandering mountain-bike trails crisscross Point Reyes National Seashore. The challenge level varies from easy to daunting, with mostly fire roads and a few single-track trails winding through densely forested knolls and sunny meadows with pretty ocean views. Because many of the hiking trails are off limits to bikes, you’ll need a bike map to figure out which ones are bike-legal. They’re available for free at the Bear Valley Visitor Center. To rent a bike, call Dave Barnett’s Cycle Analysis at 415/663-9164 or 415/663-1645, or log onto www.cyclepointreyes.com.