Maps & Posters
Water and Environmental Research Institute of the Western Pacific, University of Guam
Siegrist, Reagan, Randall, and Jenson 2008 – Geologic Map Sections, Guam Mariana Islands (scan) Siegrist et al. 2007 – Geologic Map of Agat Quadrangle, Guam Siegrist et al. 2007 – Geologic Map of Apra Harbor Quadrangle, Guam Siegrist et al. 2007 – Geologic Map of Dededo Quadrangle, Guam Siegrist et al. 2007 – Geologic Map of Hagåtña Quadrangle, Guam Siegrist et al. 2007 – Geologic Map of Inarajan Quadrangle, Guam Siegrist et al. 2007 – Geologic Map of Merizo Quadrangle, Guam *Siegrist et al. 2007 – Geologic Map of Pati Point Quadrangle, Guam *Siegrist et al. 2007 – Geologic Map of Ritidian Point Quadrangle, Guam *Siegrist et al. 2007 – Geologic Map of Talofofo Quadrangle, Guam Siegrist et al. 2008 – Generalized Geology of Guam, Mariana Islands (Stratigraph Map) Siegrist et al. 2008 – Composite Stratigraphic Sections (use with Stratigraph Map)
Links with a (*) star are links that are currently under construction. Sorry for the inconvenience.
Geologic Map Supplimentary Files: Geologic Formations of High Islands on the Philippine Sea Plate (Stratigraph Chronology)
US Department of Interior, Geologic Survey, and NOS/NOAA, in cooperation with the Government of Guam
Tracey et al. 1964 – Geologic Map Sections Guam Mariana Islands, Professional Paper 403
Tracey et al. 1964 – Sample Locality Map of Guam, Mariana Islands, Professional Paper 403-A Plate 2
1968 – Agat, Guam, Quadrangle
1968 – Apra Harbor, Guam, Quadrangle
1968 – Dededo, Guam, Quadrangle
1968 – Inarajan, Guam, Quadrangle
1968 – Inarajan, Guam, Quadrangle, Mylar
1968 – Merizo, Guam, Quadrangle
1968 – Merizo, Guam, Quadrangle, Mylar
1975 (68) – Agana, Guam, Quadrangle
1975 (68) – Agana, Guam, Quadrangle, Mylar
1975 (68) – Agat, Guam, Quadrangle, Mylar
1975 (68) – Apra Harbor, Guam, Quadrangle, Mylar
1975 (68) – Pati Pont, Guam, Quadrangle
1975 (68) – Pati Pont, Guam, Quadrangle, Mylar
1975 (68) – Ritidian Point, Guam, Quadrangle
1975 (68) – Ritidian Point, Guam, Quadrangle, Mylar
1975 (68) – Talofofo, Guam, Quadrangle, Mylar
US Geological Survey Maps
US Department of Agriculture, Soil Conservation Service, University of Guam, Government of Guam, Department of Commerce
Water and Environmental Research Institute of the Western Pacific, University of Guam
Habana & Jenson 2018 – The Northern Guam Lens Aquifer
Habana & Jenson 2018 – The Northern Guam Lens Aquifer NGWA 2018
Vann et al. 2017 – The Northern Guam Lens Aquifer
Vann et al. 2001 – Revised Topographic Volcanic Basement
Guam Hydrologic Survey Borehole Database
File Directory
Google Maps
Google Maps
One Guam Aquifer Monitoring Program
Observation Wells Plus
Web MApps
Interagency Maps Library
MAppFx Library
MAppFx: NGLA Production Well Nitrates (Valerio et al., 2023)
Selected Slides (coming soon)
Guam Waterworks Authority (Guam Production Wells and Borehole Database)
Links to files are still under construction. Please check again later.
MAppFx Library
MAppFx: Southern Guam – Ugum Watershed Streamflow Duration Curves (Habana et al., 2023)
Guam Hydrologic Survey Borehole Database
Google Maps
Production well owner and operator
Wells in Aquifer Basins
Well series or group
Well type Sub type
Year drilled
Google Maps Links
USGS Data link
Downhole Video Map (YouTube Videos)
Northern Guam Soil and Water Conservation District, Guam Department of Land Management
Courtesy of the Northern Guam Soil and Water Conservation District (NGSWCD, Joseph Santos) and the Guam Department of Land Management (GDLM). The list below is an excellent resource for historical reference and determining the use of Guamanian name places.
Links with a (**) double star are links that are currently under construction. Sorry for the inconvenience.
’00s
1900: Wheeler – Guam or Guajan Island, Exhibit A.
1902: L.M. Cox (CEC USN) – Island of Guam, 1:124,000
’10s
1913-1914: Strudevant et al. (Corps of Engineers) North Portion (Sheet 1 of 4), 1:25,000
1913-1914: Strudevant et al. (Corps of Engineers) North Central Portion (Sheet 2 of 4), 1:25,000
1913-1914: Strudevant et al. (Corps of Engineers) South Central Portion (Sheet 3 of 4), 1:25,000
1913-1914: Strudevant et al. (Corps of Engineers) South Portion (Sheet 4 of 4), 1:25,000
1915: City of Agana ~1915~, 1″ = 150′
’30s
1939: Special Military Map of Island of Guam, War Plans Section, Marine Barracks, Quantico, Wa., 1:60,000
’40s
1944: Army Map Service (AMS), 2nd Edition, Map of Guam Island, US Army, Washington DC
1942: Corps of Engineers (COE) Island of Guam (Uruno Point, Sheet 1 of 11) 1:20,000
1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Ritidian Point, Sheet 2 of 11) 1:20,000
1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Tumon Bay, Sheet 3 of 11) 1:20,000
1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Apra Harbor, Sheet 5 of 11) 1:20,000
**1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Agana Bay, Sheet 6 of 11) 1:20,000
1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Agana Bay, Sheet 6 of 11, v2) 1:20,000
1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Pagat Point, Sheet 7 of 11) 1:20,000
1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Agat Bay, Sheet 8 of 11) 1:20,000
1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Agat Bay, Sheet 8 of 11, v2) 1:20,000
1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Talofofo Bay, Sheet 9 of 11) 1:20,000
1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Port Merizo, Sheet 10 of 11) 1:20,000
1942: Corps of Engineers (COE) (1922 and 1942) Island of Guam (Port Inarajan, Sheet 11 of 11) 1:20,000
1944: Army Map Service (AMS), 2nd Edition, Map of Guam Island, US Army, Washington DC
’50s
1954: AMS (AFFE) Edition 1 Guam
’80s