California Native Plant Society

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Lawson’s Landing


Tomales Dunes is not only a valuable, fragile natural resource; it is also the site of Lawson’s Landing, a large agricultural operation and the biggest RV campground on the coast of California. Lawson’s Landing has 233 permanent RVs and up to 1,000 additional RVs each night. Cars and RVs damage the sensitive dune wetlands. On busy weekends, Lawson’s Landing is transformed into the biggest town in West Marin.

Lawson’s Landing has operated for decades without the required County and Coastal Commission permits. Apart from porta-potties, the campground is served by about 100 primitive, un-permitted cesspits, most sited along a seawall next to Tomales Bay. A sand quarry operated in the dunes for years, but has recently been forced to close due to permit violations. Invasive European beach grass has been planted to protect the campers from being bombarded by wind-blown sand, but it is taking over the mobile dunes, and if unchecked will destroy them within a very few years.

Vegetation Classifications:

The California Department of Fish and Game maintains the California Natural Diversity Database (CNDDB). The CNDDB program uses NaturServe's Heritage Program methodology defined for Natural Community Conservation Ranks to confer rarity rankings for vegetation alliances (see

Alliances marked with a G1 through G3 are rare and threatened throughout their range. Alliances marked with a G5 and an S1 through S3  are secure through their range outside the state but are rare and threatened in California. A G4 / S4 alliance may or may not be endemic to California and is secure statewide.

Based on vegetation types described in Baye and Wright 2004 (groundtruthing surveys are required to confirm these findings), rare and unusual vegetation types of the Tomales Dunes area include (but are not limited to) the following:

Dune communities (CNDDB rarity rankings (G = global / S = State))

  • Dune Mat (Abronia latifolia–Ambrosia chamissonis) Alliance (G3 / S3)
    • Including associations with beach-bur (Ambrosia chamissonis), yellow sand-verbena (Abronia latifolia), pink sand-verbena (Abronia umbellata), sea rocket (Cakile)lizard-tail (Eriophyllum staechadifolium), yellow bush lupine (Lupinus arboreus), and dune tansy (Tanacetum camphoratum)
  • Sea Lyme Grass (Leymus mollis) Alliance (G4 / S2)
    • Including association with sea lyme grass (Leymus mollis), Vancouver wildrye (Leymus x vancouveriensis),and Pacific wildrye (L. pacificus)
  • Silver Dune Lupine–Mock Heather Scrub (Lupinus chamissonis–Ericameria ericoides) Alliance (G3 / S3)
    • Including associations with mock heather (Ericameria ericoides), yellow bush lupine (Lupinus arboreus), and many other perennial and annual herbs


Dune slack, coastal wetland and marsh communities:

  • Sitka Willow (Salix sitchensis) (G4 / S3?) Provisional Alliance,and Arroyo Willow (Salix lasiolepis) Alliance (G4 / S4)
    • Including associations with arroyo and Sitka willows
  • Salt Rush (Juncus lescurii)Herbaceous Alliance (G3 / S2?)
    • Including association with Brewer's rush (Juncus breweri)
  • Pale Spikerush (Eleocharis macrostachya) Alliance (G4 / S4)
    • Including associations with pale spikerush (Eleocharis macrostachya), Western lilaeopsis (Lilaeopsis occidentalis), and common threesquare (Schoenoplectus pungens)
  • Pacific silverweed (Argentina egedii) Alliance (G4 / S2)
    • Including associations with Pacific silverweed (Potentilla anserina ssp. pacifica =Argentina egedii), pale spikerush (Eleocharis macrostachya), and California saltbush (Atriplex californica)
  • Saltgrass (Distichlis spicata) Alliance (G5 / S4)
    • Including associations with saltgrass (Distichlis spicata),pickleweed (Sarcocornia pacifica),marsh jaumea (Jaumea carnosa), seaside arrow-grass (Triglochin striata), and other plants
  • Pickleweed (Sarcocornia pacifica) Alliance (G4 / S3)
    • Including associations with pickleweed and saltgrass (Distichlis spicata)
  • Ditch-grass and Widgeon-grass (Ruppia (cirrhosa, maritima)) Alliance (G4? / S2)
    • Including association with widgeon-grass (Ruppia maritima)
  • Pondweeds (Stuckenia (pectinata)–Potamogeton spp.) Alliance (G3G5 / S3?)
    • Including associations with leafy and broadleaf pondweeds (Potamogeton foliosus and P. nodosus)

The G indicates the alliance's rarity and threat globally, and the S indicates the alliance's rarity and threat in California.
Global and State Ranks
G1 S1: Fewer than 6 viable occurrences worldwide / statewide, and/or up to 518 hectares
G2 S2: 6-20 viable occurrences worldwide / statewide, and/or more than 518-2,590 hectares
G3 S3: 21-100 viable occurrences worldwide / statewide, and/or more than 2,590-12,950 hectares
G4 S4: Greater than 100 viable occurrences worldwide / statewide, and/or more than 12,950 hectares
G5 S5: Demonstrably secure because of its worldwide / statewide abundance

CNPS Plant Protection Recommendations:

CNPS considers Marin County’s review of and action upon the proposal to be deficient as regards both the process and the final outcome.

The County used a baseline environmental assessment that included a wide range of unpermitted and unlawful activity resulting in a report that seriously understated the environmental impacts of the campground and associated infrastructure. Further, the County failed to require a systematic biological survey and mapping of the unusual plant species and communities for which the site is known. The project was thus designed without adequate regard for the protection of these important resources. We hope that the Commission’s decision will rectify these shortcomings.

CNPS understands that the Commission will give de novo review to this matter and that the applicant’s proposal has changed since 2008. We therefore emphasize the following points here:

  • As described by coastal plant ecologist Peter Baye in a 2004 survey, the Lawson’s Landing site supports (or did support) a striking array of rare or unusual plants:
    • Dune tansy, southern form (Tanacetum camphoratum)[only Marin County population]
    • Sonoma spineflower (Chorizanthe cuspidata var cuspidata)[northern edge of range]
    • Tidestrom’s lupine (Lupinus tidestromii)[federally endangered; last seen on site in mid-1990’s]
    • Striate arrow-grass (Triglochin striata)[only Marin county population]
    • Unnamed hybrid of Leymus pacificus [anomalous endemic population]
    • Undetermined horsetail (Equisetum)[ unknown hybrid or subspecies; dwarf in stature]
    • Unidentified species of Chara [genus not usually found in coastal habitats or dune ponds]
    • Western Lilaeopsis (Lilaeopsis occidentalis)[at edge of range; population unusually large]
    • Pondweed (Potamogeton foliosus, P. nodosus) [uncommon in California]

The last six of these taxa occur in the site’s wetlands. None is mentioned in the Revised Project Description, dated June 6, 2011, nor do their precise locations in relation to the proposed development  appear in the record, to the best of our knowledge.

CNPS believes that the presence of no fewer than three taxa of taxonomic uncertainty together with 5 others with biogeographic significance warrants the adoption of strong protective measures. Being rare or thriving outside the heart of these species’ range, these plants can be considered ecological or genetic outliers-- that is, they could be slightly differently adapted to their environment or resistant to disease, pathologies or environmental changes that could wipe out the core populations. Only if adequately protected can these unusual plants serve as refugia or a colony of survivors in the event of a population collapse brought about, for example, by climate change.

The Marin Local Coastal Program [LCP] embraces the concept of conserving such unusual populations in its definition of “sensitive habitat areas,” stating “such habitat may… be unique, rare or fragile, provide habitat for rare or endangered species of wildlife and thus be vital to species’ survival or be of particular scientific or educational interest.” LCP Unit II at 70 [emphasis added]. Certainly these taxa would be of scientific interest and the presence of several such plants within the same vicinity suggests that the site’s wetlands (or some of them) may be ecologically unique.

  • Any approval of a coastal development permit should require the applicants to preserve and/or restore the hydrology supporting the unusual plants discussed above. For example, the existing drainage ditches should be removed so that the unusual dune slack wetlands and other mesic habitat areas may function naturally. Wetland buffer zones of sufficient width should also be established and planted with natives and natural succession. LCP Unit II Sec. 4d, p. 74.
  •  Livestock grazing should not be permitted in wetlands or buffer zones. Grazing in soft, low-nutrient wetlands is harmful to their ecological functioning. The feet of heavy cattle disturb the soft substrate and roots of rhizomatous vegetation; urine and feces increase the nutrient level. Both of these factors encourage invasions of exotic plants, such as velvet grass and Kikuyu grass. Removing cattle will aid in the protection of the unusual wetland species discussed above.
  • Rarity aside, all development, including RV and automobile parking, should be sited so as to avoid “sensitive habitat areas” which are protected under both the California Coastal Act and Marin’s Local Coastal Program. Elaborating on the definition of these areas, the Marin LCP states: “such habitats may serve as prime examples of particular natural communities…” LCP, Unit II, p. 70 [emphasis added]. 

The campground site consists almost entirely of “sensitive habitat areas,” several of which exemplify recognized plant communities or vegetation types: coastal dune scrub, mobile dunes, wetlands, and dune slacks. Any approved plan should protect these areas to the maximum extent possible. 

  • The conditions of any coastal permit approval should specify resource management objectives and measures for achieving them. The permit conditions should address threats to sensitive resources in and near the quarry area, mobile dunes, wetlands and buffers, and all populations of rare and unusual species. In addition to the requirements discussed above, such conditions should include:
    • invasive plant removal to the extent feasible
    • reversal of the loss of mobile dunes to the extent feasible
    • prevention of trampling, parking or driving on sensitive plant communities by the campers and other visitors 

While the execution of an adequate conservation easement would, in theory, address our concerns, there is much uncertainty about the availability of public or private funds to bring this about and, most importantly, it is unknown whether the wetlands and dune habitats that support the site’s unusual plants are within the proposed easement area

CNPS recognizes the value of maintaining public access to the Tomales Dunes and the special difficulty of balancing this interest with resource protection in this matter. Still, the fact that the campground has existed illegally for decades should not absolve the applicants of the responsibility to protect and manage the site’s unique natural resources. CNPS is counting on the Commission to enforce the provisions of the Local Coastal Program by assuring that the project is designed and constructed so as to adequately protect these areas.

Reference:  Peter Baye, Biogeographic Assessment of Tomales Dunes, California: Vegetation, Flora and Invertebrates (August 2004)

Current Status:

The California Coastal Commission will be reviewing the status of Lawson’s Landing on July 13th at the Marin Civic Center around 10:00 AM. Please join these hearings to ensure Lawson’s Landing is properly protected.


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