Search Results
1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, and 1994. King, Philip B., Arndt, Raymond E., Schruben, Paul G., Bawiec, Walter J., and Beikman, Helen M. This polygon shapefile shows the boundaries of geologic units within the United States. This layer is part of the Geologic Map of the United States... Geological Survey (U.S.).
1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, and 2005. Geological Survey (U.S.). This polygon shapefile portrays the state boundaries of the United States, and the boundaries of Puerto Rico and the U.S. Virgin Islands. The map l... Geological Survey (U.S.).