Last Data Base Update:

July, 2009

Disclaimer for a Provisional Data Base: "The data you have secured from this USGS Data Base are provisional and subject to revision. The data are released on the condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use." Distribution Liability: "Although the data has been processed on the computer system at the U.S. Geological Survey, U.S. Department of the Interior, no warranty, expressed or implied, is made by the Geological Survey regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. No responsibility is assumed by the U.S. Geological Survey in the use of these data."