Bedwell Bayfront Park in Menlo Park is 160 acres of open space, surrounded by the Don Edwards San Francisco Bay National Wildlife Refuge. The park is easily accessible from the 101 and offers plenty of outdoor recreation opportunities from bird watching to hiking, running to mountain biking, and is a very popular place for walking the dog. There is a huge network of trails throughout the entire open space with approximately 100 feet of gain to reach the highest points.
The perimeter trail is listed here and the entire loop around Bedwell Park is a 2.3-miles. Most of the surfaces are old asphalt roads, crushed gravel paths and dirt trails.
Check out the Official Route and Triplog.