As of 2005, state and federal agencies conserved approximately 14 percent of the total land base, or over 324.6 million acres, which averages to approximately 1 acre of land, conserved for each resident. However, in the face of unprecedented population growth, the number of acres per capita is bound to decrease significantly in the coming years.

From 1998 through 2005, 18.4 million acres of land were conserved in the United States; by both states and the federal government in approximately equal proportions (about 9 million acres each). Almost two-thirds (72 percent) of these lands were purchased in fee title, while the remainder was protected through conservation easements. States expended over $13 billion in this time period for land conservation (89 percent of total expenditures), while the federal government spent $1.5 billion. In other words, on an annual basis, the states spent an average of $1.6 billion to conserve lands (at an average cost of $1,500 an acre) while the federal government expended an average of $136.5 million a year (at an average cost of $750 per acre).

Within the Conservation Almanac, conservation lands or acreage constitutes lands removed from the inventory of developable lands and, as much as possible, lands removed from the inventory of lands available for commercial and/or intensive use. The acreage and cost data included in the Conservation Almanac is through the end of 2005.