Historic Landmarks of San Francisco

This marker is at the approximate location of the first iteration of Mission San Francisco de Asís, popularly known as Mission Dolores. It is but a few blocks from the present church. A second bronze plaque, opposite the first, presents a map showing the two mission sites as well as the purported Dolores Lagoon. Recent research indicates that no such body of water as shown on the map ever existed! The topography is wrong. What probably did exist was an ephemeral arm of Mission Bay, a branch of San Francisco Bay. Mission Bay once extended far inland from its present shoreline, before the area was filled in. A tidal inlet probably existed between Harrison and South Van Ness Streets, extending south to 20th Street and navigable as far as 16th and Harrison Streets. In times of heavy rain and/or very high tides a seasonal wet area may have extended westward from the tidal inlet and covered some of the southern portion of the mythical Dolores Lagoon. The maximum depth of this extension was probably no more than a few inches. There certainly was never a freshwater lagoon in the location shown on the plaque.