This nature preserve is just between the Industrial/commercial section f Bel Marin Keys Blvd and the housing of the area. It’s a large draw for many birds including swans! I’ve counted 8 of them one time and others have claimed up to as many as 13 though I wonder if some egrets were counted. The Pond backs up to the Hamilton section of the Bay trail. Take US 101 north to Bel Marin Keys exit, turn right onto Bel Marin Keys Blvd, continue 1.1 mile, Pacheco Pond is on your right, turn into the small parking lot on your right.