Join Tom and Owen Slater for close views of waterfowl and occasional bitterns and rails from the boardwalk over Oso Flaco Lake and marsh. Bird two prime willow habitats for wintering warblers. Includes 2-3 miles of slow walking. Moderate. Great trip to join if you're heading home going south. Meets at Oso Flaco parking lot, 3004 Oso Flaco Lake Road, Arroyo Grande. State Parks requires a parking fee of $5.