Amy reminds me to mention another hike we both took this weekend out at the Rush Creek Open Space Preserve in Marin County. It's about 4 miles, fairly flat--"not manly and strenuous," as Amy notes, but "a perfect date hike." What's particularly cool about Rush Creek is that it's right off the 101, as the map above shows, but walk just a few hundred yards along the trail and the highway noise recedes to a dull roar and eventually disappears altogether. And this is probably the best time of year to be there--nice and warm, but still plenty of water in the marsh.
A few notes: Bring binoculars, as both Rush Creek Marsh and Cemetery Marsh are full of birds--I've never seen more egrets (or heron, or whatever they were) in one place before.
Even though it's possible to do a full loop by taking the Pinheiro Fire Road out to Bugela Lane and return to the trailhead via Atherton Avenue, don't bother--the roadside trail is well off the roadway, but that area's pretty developed and boring. Better to do a semi-loop around Cemetery Marsh and return to the trailhead by walking along Rush Creek Marsh, the way you came in.
Some trails (unmarked and not on the map) branch off the Rush Creek Fire Road along the eastern edge of Cemetery Marsh and presumably head up into the hills on the eastern side of the preserve. Looked well worth exploring further.
And at the far northern edge of the preserve, at the terminus of the Rush Creek Fire Road, there's a fantastic picnic spot right on Black John Slough. Very peaceful, except for the occasional small aircraft coming from a nearby field.
