221. The Appalachian National Scenic Trail Publication/Creation: [Washington, D.C.] : [publisher not identified], [1973] Resource Type: Map Access & Availability: Loading
222. Approximate change in water levels in the Chicot and Evangeline aquifers 1977-88 and 1987-88, and measured compaction 1973-88, in the Houston-Galveston region, Texas Author/Creator: Gabrysch, R. K. Publication/Creation: [Reston, Va.] : U.S. Geological Survey, 1988 Resource Type: Map Access & Availability: Loading
223. Approximate location of the 10,000-milligram-per-liter dissolved-solids boundary in the Silurian and Devonian carbonate-rock aquifer, southwestern and northern Indiana Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Reston, Virginia : U.S. Department of the Interior, U.S. Geological Survey, 1994 Resource Type: Map Access & Availability: Loading
224. Approximate potentiometric surface for the aquifer unit A2, southeastern coastal plain aquifer system of the United States, prior to development Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
225. Approximate potentiometric surface for the aquifer unit A3, southeastern coastal plain aquifer system of the United States, prior to development Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
226. Approximate potentiometric surface for the aquifer unit A4, southeastern coastal plain aquifer system of the United States, prior to development Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
227. Approximate water-level changes in wells completed in the Chicot and Evangeline aquifers, 1977-91 and 1990-91, and measured compaction, 1973- 90, in the Houston-Galveston region, Texas Author/Creator: Barbie, Dana L. Publication/Creation: [Reston, Va.] : U.S. Geological Survey, 1991 Resource Type: Map Access & Availability: Loading
228. Aqaba Publication/Creation: [S.l.] : Maps.com, c1997 Resource Type: Map Access & Availability: Loading
229. Aqueous geochemical data from the analysis of stream water samples collected in August 2004, Taylor Mountains, 1:250,000 scale quadrangle, Alaska Publication/Creation: Reston, Va. : U.S. Geological Survey, 2006 Resource Type: Map Edition: Version 1.0. Access & Availability: Loading
230. Aquifer-test results, direction of ground-water flow, and 1984-90 annual ground-water pumpage for irrigation, lower Big Lost River Valley, Idaho Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Boise, Idaho : U.S. Department of the Interior, U.S. Geological Survey, 1992 Resource Type: Map Access & Availability: Loading