Formed in 1981, the LTA provides technical support to a network of land trusts in the United States. The LTA performs a census that keeps track of the land protected by local and regional land trusts. The last census, conducted in 2003, reported that these trusts have protected almost 9.4 million acres of land in the United States, double the 4.7 million acres recorded in the 1998 survey.
The California Council of Land Trusts acts as a unified voice for more than 200 land trusts working in local communities throughout California. The Legislation Watch link is useful.
Wikipedia article gives description of various types of land trusts plus a little history. The Conservation Land Trust is covered toward the bottom of the page.
Conservation is humanity caring for the future. -- Nancy Newhall