Tomales Dunes

In 1998, EAC called Tomales Dunes “Marin’s least-known ecological treasure.” Today, it is recognized as a nationally important coastal resource that deserves protection.

photo: Sue Vander Wahl

Thanks to EAC’s leadership, commitment, passion, and long hours of work, we succeeded in protecting this amazing place!

To put it into perspective, in 1998, Marin County was about to approve – with no environmental review – the Lawsons’ application, which called for:

  • camping on 83 acres of functioning wetlands and other sensitive habitat;
  • no buffers for wetland or dune scrub
  • continued artificial drainage of wetlands
  • no public access to a large part of the campground, in favor of small
  • group of “travel trailer” owners.
  • a new septic system with a leachfield situated in dunes and wetland;
  • continued sand quarrying;
  • no controls on grazing in wetlands;
  • no protections for listed species, including western snowy plover and
  • California red-legged frog;
  • no plans for removal of invasive species such as European beachgrass;
  • no plans for introduction of rare species, such as the Myrtle’s
  • silverspot butterfly;
  • no conservation easement
  • no management or restoration plans at all;
  • no alleviation of the traffic impact on DIllon Beach; and
  • no undergrounding of utilities to protect viewshed from public lands.

After 13 years of work on this issue, the final Coastal Development Permit:

  • allows camping on 18 acres of sensitive habitat (an 80% reduction over 1998);
  • mandates 100 foot wetland buffers and 50 foot dune scrub buffers;
  • requires restoration of the natural wetland hydrology, except for camping
  • areas;
  • requires removal of several roads through wetlands;
  • eliminates the private travel trailers and opens all camping to public access;
  • moves the leachfield out of sensitive habitat;
  • does not allow sand quarrying;
  • restricts grazing in wetlands;
  • puts 465 acres under a permanent conservation easement
  • has a Protection, Restoration, and Enhancement Plan, the goal of
  • which is to restore and enhance the dunes-wetland complex by
  • restoring natural hydrology of wetland,
  • protecting listed species,
  • preventing spread of invasive species,
  • planting native species to create habitat for Myrtle’s silverspot butterfly, etc.;
  • has a traffic plan that sets standards for traffic flow and safety;
  • and provides for additional measures if those standards are not met;
  • requires undergrounding of utilities.

This is a great coastal victory!  EAC is very grateful to everyone who supported our efforts to protect the Dunes and for your indispensable part in it!!

Tomales Dunes is actually a complex of several distinct habitats: mature mobile dunes, central dune scrub, dune prairie, and dune wetlands.  And it is surrounded by and connected to a rich coastal environment that includes coastal prairie, coastal scrub, salt marsh, tidal flats, bay, and ocean. This extraordinary site, which includes a 230 foot high dune known as Little Sugarloaf, supports at least 9 special-status species.

These dunes are responsible for much of the unique character of Tomales Bay and the surrounding area.  They provide a buffer to the prevailing westerly winds and modify the tides, creating a relatively protected bay, one that is more complex, hospitable, and biologically diverse than a simple marine inlet. In addition, the rich variety of dune and coastal environments adds to the diversity of habitats in the Bay, making it a year-round home and an important migratory stop-over for a variety of bird species. More than 40 species of waders and waterfowl find their winter roosting and feeding grounds at Tomales Dunes.  And it is one of only eight sites in North America where Pacific golden plovers (Pluvialia fulva) have been known to overwinter.

So far, however, this still is one of the few dune systems in California that has a vital population of native dunegrasses, including a recently discovered and still-undescribed species.  In addition, there are mobile dunes here, the kind we think of when we call to mind the classic dune—completely unvegetated and constantly shifting.  As winds push these mobile dunes slowly inland, an ever-changing series of new habitats is created.

Winds also carve depressions in the exposed sands of the bare dunes.  Where these depressions are fed by groundwater, rain, or intermittent surface streams, they develop into rich and unique seasonal wetlands, ranging from freshwater ponds, to marshes, to wet meadows”. Tomales Dunes is a wetland paradise, with the richest collection of these seasonal wetlands–known collectively as “dune slacks”–in central California. The same subterranean waters that feed the slacks have also created an amazing “Grand Canyon of the Sands”, which is recut and reshaped in wet winters by a rain-fed underground spring, the only such dune canyon in central California.

Current Use

EAC continues to work with the Lawsons family as they implement the many provisions of their coastal development permit, particularly the Tomales Wetlands-Dunes Complex Protection Restoration and Enhancement Plan (PREP). The PREP is already underway and EAC is working with the Coastal Commission and the Lawson family to ensure the protection of the wetlands, dunes, and wildlife of this exceptional coastal site.

Download Tomales Dunes Quick Facts Sheet