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The Land Trust of Napa County


In northern California, the Land Trust of Napa County has evolved its use of GIS over a decade, going from simple project maps, to countywide posters, to full conservation planning and more sophisticated analysis of potential acquisition opportunities. This work is key in focusing the daily work of the trust, communicating to donors, keeping trustees informed and presenting the accomplishments of the trust to the public.


The mission of the Land Trust of Napa County is to protect the natural diversity, scenic open space and agricultural vitality of Napa County by preserving lands with significant conservation values for present and future generations and by fostering an appreciation and understanding of the natural environment.

The use of GIS has had three major stages, each with their own objectives:

  1. Basic - mapping support for key land acquisition activities, through preparation of project maps
  2. Intermediate - use of carefully designed display posters to educate donors and other stakeholders about the land trust's work, along with continuing project mapping support
  3. Advanced - use of GIS to create a highly detailed conservation priority plan for the county, and to continue to expand on the uses noted in other two phases


Stretching nearly 50 miles north from San Francisco Bay, Napa County is home to some of the finest wine grapes in the world.  But the county and its 130,000 residents have a lot more assets than just the fruits of vines and remarkably scenic vistas. Extending into rugged backcountry of the 480,000 acre county is habitat that contains almost 70 imperiled species and a number of important natural communities – one of the highest figures for any county in the United States.

Sitting at the north end of the fourth largest metropolitan region in the United States, Napa faces huge demand to use these lands for different purposes, including expanded vineyards, rural estates and suburbs.  While the county has pursued policies for three decades to maintain its 130,000 acres of agricultural land, only about one-fifth of its land area is securely protected for open space, mostly in a very large and remote holding of the U.S. Bureau of Land Management.

For 30 years, the Land Trust of Napa County has been working for conservation in the county, which does not have a county park district or any other special program to protect open lands through acquisition.  With 1,500 members, over a hundred volunteers and a small professional staff, the land trust has protected over 45,000 acres of land through easements and other acquisitions.

In the late 1990s, the land trust was involved in a regional inventory of protected lands, conducted by GreenInfo Network. From this exposure to what GIS could provide in the way of useful data, the trust commissioned a GIS map highlighting its conservation accomplishments. This carefully designed poster map has become a branding image for the organization, displayed and recognized throughout the county. It is also used a gift from the Land Trust to Board Members and other deserving recipients for their efforts in preserving land in Napa county.

By 2000, the land trust had begun to use GIS internally (ESRI ArcView software). This allowed the trust to quickly generate maps of proposed acquisitions and other maps that did not need extensive effort to design and produce.

In 2003, the Napa Land Trust began its conservation priority project, working with a consulting team:  

  • A planning consultant helped develop and manage the overall planning process;
  • The Nature Conservancy and its partner, NatureServe, applied their innovative GIS conservation planning tool, Vista, to better assess biodiversity;
  • New and highly detailed vegetation data for the model was developed by the Institute for California’s Environment (ICE) University of California at Davis;
  • GreenInfo Network then worked with the trust’s team to apply GIS to define scenic zones, agricultural areas and needed recreational lands, and to design the maps that would convey this information to the trust’s stakeholders and the public.

The method used in the conservation planning was to identify key landscape linkages that would maintain the composition, structure, and vitality of important ecological systems in the county. Endangered, threatened or declining terrestrial or aquatic species were also identified as targets for protection. Based on this, protection priorities were set using the conservation values and measures of vulnerability to development.  All of this data was correlated to ownership boundaries provided by the County of Napa, allowing the land trust to understand not only the ecological character of the landscape but also the nature of each landowner’s holdings.

The conservation plan was published in a special report that is setting the trust’s direction for the next decade.

Since the conservation plan, the land trust has used GIS to assist with implementing its priorities, including developing a paper and electronic atlas the entire county.  For example, in late 2005, the land trust applied GIS to a particular opportunity, a large ranch that was up for sale, using it to assess properties that were in the viewshed of the proposed acquisition, in order to help the land trust identify other owners who might be approached for donations to support protecting the ranch.

The Land Trust of Napa County has an ambitious goal to save an additional 17,000 acres of land by 2010, increasing its protected lands from 50,000 or more acres. With eight years of using spatial analysis to advance its work, the trust is confident that GIS will be a key partner in this next campaign.


John Hoffnagle, Executive Director - The Land Trust of Napa County
Tina Stott, planning consultant, Pacific Municipal Consultants
Kristen Barker, Natureserve
Maegan Leslie, GreenInfo Network

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© Land Trust GIS 2006