Open houses/special displays/activities at Maysonnave House, Blue Wing Inn, State Park/Casa Grande/Barracks and Depot Museum. Passports available at each site; get them stamped at all four sites and show them near the Vallejo statue on the Plaza for a free ice cream cone courtesy of La Michoacana Ice Cream until 3:00 p.m. Free and open to the public. All non-members of the sponsor organizations may receive complimentary 2019 memberships in the Sonoma Valley Historical Society, Sonoma Petaluma Parks and the League. Further details in the I-T.