The Ross Valley's Historic Marshlands
1850's & Present

 1850's
Present day

The Ross Valley, like many of the former marshland valleys of the San Francisco Bay area, has been significantly impacted by human development. The majority of the marshlands (light green on the left above) that occupied the Ross Valley until the 1850's have been filled for residential and commercial use.

The closeup of the Ross Valley obtained from the REGIS materials at Berkeley (slightly modified because the original did not include the GG Transportation dredge spoil disposal site, the new Village Shopping Center in Corte Madera, and the garbage dump fill (now the site of the Home Depot) in San Rafael at the top of the map) With the development of the Golden Gate Ferry Terminal  (the large red patch on northern side of the valley) the Bay Conservation and Development Commission's "mitigation" requirement for damaging marshland and ecological habitat of the bay for "development" led to the restoration of historically diked wetlands to their natural condition of salt marsh along Paradise drive. As well, the building of the Village Shopping Center along Hwy 101, estabished a "tide range controlled" marsh/flood control structure to the north of the shopping center that is maintained by the City of Corte Madera. Both of these developments reversed a historic pattern of decreasing surface area of the bay and in the case of the Ferry terminal project's breaking the levees of the marsh in 1981 led to the first increase in over 100 years. 

Another marsh resoration project, this one funded by the local residents, was accomplished up the Ross Valley's Corte Madera Creek, near the site of the historic Bon Air Hotel and the modern Marin General Hospital. There are concerns about this restoration since a South American cordgrass has established itself in the restored marsh and has expanded its range into the natural marsh along the main Corte Madera Creek tidal channel. The Friends of Corte Madera Creek have further information on the watershed.