Base of Principal Aquifer for Parts of the North Platte, South Platte, and Twin Platte Natural Resources District, Western Nebraska

By

Christopher M. Hobza, Jared D. Abraham, James C. Cannia, Michaela R. Johnson, and Steven S. Sibray

METHODS (cont.)

After initial processing by SkyTEM, the data were inverted using 

the Aarhus Geophysics Aps, (Aarhus, Denmark) program Workbench 

(Auken and others, 2009). To make the AEM data useful for geologic 

interpretation, numerical inversion converted measured data into a 

depth-dependent subsurface resistivity model, which was displayed 

as a resistivity profile. The inverted resistivity model (referred to 

hereafter as inverted AEM profiles), along with sensitivity analyses and test-hole information, were used to identify hydrogeologic 

features such as bedrock highs and paleochannels. A depth of investigation (DOI) calculation using the method given in Christiansen and 

Auken (2010) for each sounding is included in appendix 2 of U.S. 

Geological Survey Crustal Geophysics and Geochemistry Science 

Center (2014). The DOI can be defined as a critical depth below 

which the resistivity value is no longer constrained and interpretations of layer boundaries applied below DOI should be used with 

caution. Details on the data processing and inversion modeling can 

be located in Smith and others (2009, 2010). 

An interpretation of the location of the BOA was completed 

using a GIS that output x, y, and z coordinates. Before interpreting 

the inverted AEM profiles, several complementary datasets were 

included and graphically displayed in two- and three-dimensional 

GIS environments. Complementary data included test-hole lithology, 

test-hole geophysical logs (including natural-gamma and normal 

resistivity; University of Nebraska-Lincoln, Conservation and Survey Division, 2014; J.C. Cannia, U.S. Geological Survey, written 

commun., 2012; Hobza and Sibray, 2014; T.A. Kuntz, Adaptive 

Resources Inc., written commun., 2012), TDEM resistivity models 

(Abraham and others, 2012; M.A. Kass, U.S. Geological Survey, 

written commun., 2014), airborne measurements of the intensity 

of 60-hertz power-line interference, airborne measurements of 

the magnetic total-field intensity, aerial photographs (Esri, 2014), 

unpublished bedrock outcrop maps (R.F. Diffendal, Jr., University of 

Nebraska-Lincoln, Conservation and Survey Division, unpub. data, 

2013; J.B. Swinehart, University of Nebraska-Lincoln, Conservation and Survey Division, unpub. data, 2013), and the 10-m digital 

elevation model (DEM; Nebraska Department of Natural Resources, 

1998). The inverted AEM profiles were displayed as colored resistivity profiles within the GIS environment. To assist interpretation, 

the inverted AEM profiles were plotted using a consistent color 

scale, and all of the datasets for each NRD were placed in the same 

projected coordinate system. This allowed the data to be examined 

at varying spatial scales, and for data to be iteratively displayed or 

hidden to fully examine how the geophysical data correlated with 

complementary datasets.

The overview of the process of creating BOA maps from 

inverted AEM profiles is described below with a more detailed 

discussion included in the subsequent subsections. Geologic interpretation involved manually picking locations (BOA elevations) on 

the displayed AEM profile by the project geophysicist, hydrologist, 

and geologist. These locations, or picks, of the BOA (herein referred 

to as BOA picks; typically the top of the Brule) were then stored in 

a georeferenced database. The BOA picks were made by comparing 

the inverted AEM profile along a flight line to the known lithology 

of the area based on lithologic descriptions and borehole geophysical 

logs from test holes. Using a GIS to view all available data at one 

time in a spatially georeferenced manner provides a high degree of 

confidence in the elevation values for the picks. The point dataset 

of the BOA picks’ elevation was the input to a surface-interpolation 

algorithm of the GIS. A contouring algorithm subsequently was used 

to construct contours of the BOA elevation. The generated contours 

then were manually adjusted based on the interpreted location of 

paleovalleys eroded into the BOA surface and associated bedrock 

highs. The interpreted BOA surface is the result of erosion and subsequent valley-filling fluvial deposition from eastward draining streams 

(Cannia and others, 2006), and therefore is not expected to contain 

enclosed depressions. These newly revised contours were compared 

with land-surface elevation as a consistency check. Where the interpolated BOA intersected land surface, the contours were reshaped 

manually to follow the 10-m DEM. This was done to correct areas in 

the final dataset where the BOA elevation exceeded the land surface. 

As another consistency check, the DOI information (appendix 2, U.S. 

Geological Survey Crustal Geophysics and Geochemistry Science 

Center, 2014) was compared to the BOA-pick depth. In nearly every 

case, the BOA picks were above the DOI depth. In cases where 

the BOA picks exceeded the DOI, the supported BOA contours are 

dashed to indicate the contour locations are inferred (fig. 2); however, 

the inferred BOA contours and BOA picks are included in the final 

GIS dataset because they are supported by test-hole and other complementary geophysical data.

NORTH PLATTE AND SOUTH PLATTE NATURAL 

RESOURCES DISTRICTS BASE-OF-AQUIFER 

INTERPRETATION

The BOA picks derived from the inverted AEM profiles acquired 

in 2010 were added to the georeferenced database used by Abraham 

and others (2012). All BOA-pick elevations were referenced as feet 

above the National Geodetic Vertical Datum of 1929 (NGVD 29; 

fig. 2). This was done by first sampling the elevation at each BOApick location from a 10-m DEM (Nebraska Department of Natural 

Resources, 1998) and subtracting the BOA-pick depth from the corresponding inverted AEM profile. Point locations of BOA elevations 

were picked from inverted AEM profiles and correlated to borehole 

geophysical logs confirming the base geologic unit. These locations 

were exported to Esri shapefile format to provide more detailed 

elevation control in redefining the BOA contours from Abraham and 

others (2012). Point locations with BOA elevation from existing 

wells and test holes (Cannia and others, 2006) used in the original 

interpolation of the BOA (Abraham and others, 2012) were used 

again as elevation control in the contours presented in this report. 

Additional point locations for BOA elevation were provided from 

interpreted resistivity models of the TDEM surveys (M.A. Kass, 

U.S. Geological Survey, written commun., 2014) and test hole drilling (Hobza and Sibray, 2014; T.A. Kuntz, Adaptive Resources Inc., 

written commun., 2012). 

The georeferenced database of BOA picks from the interpretation of the new inverted AEM profiles was used to create the new 

BOA contours (fig. 2). Preliminarily, 50-ft (15.2-m) contours were 

generated using the ArcGIS application, Topo to Raster (Esri, 2014; 

Hutchinson, 1988, 1989, and 1996; Hutchinson and Gallant, 2000; 

Hutchinson and others, 2011). The Topo to Raster tool interpolated 

the bedrock-topographic surface described by the previous version 

of BOA contours (Abraham and others, 2012) to produce a raster 

version of the interpolated BOA-elevation surface. The interpolated 

surface was refined manually to have no cells above land surface 

elevation (as represented by the 10-m DEM). The GIS tool, contour, 

generated a set of hypsometric contours from the gridded surface 

with the specified interval of 50 ft (15.2 m; Esri, 2012a). The generated contours then were manually adjusted based on the interpreted 

location of paleovalleys eroded into the BOA surface and associated 

bedrock highs. The new BOA contours for this report (fig. 2) are a 

modification of the previously mapped tops of the Brule or Cretaceous units, which collectively are known as a confining unit where 

they are in contact with the primary aquifer presented by Abraham and others (2012). All GIS datasets for the new BOA surface 

are included at the following link (http://pubs.usgs.gov/sim/3310/

GIS_files). 

TWIN PLATTE NATURAL RESOURCES DISTRICT BASEOF-AQUIFER INTERPRETATION

For the TPNRD, the most recent BOA map published was 

completed by Cannia and others (2006), and was used in recently 

published COHYST groundwater models (Carney, 2008; Luckey 

and Cannia, 2006). This dataset included 100-ft (30.5-m) contours 

referenced to the NGVD 29 datum. Since 2008, changes have been 

made to the primary groundwater model used by the TPNRD, which 

is now referenced to the North American Vertical Datum of 1988 

(NAVD 88) with all elevations given in meters. The depth to the 

BOA at available test holes (J.C. Cannia, U.S. Geological Survey, 

written commun., 2012; University of Nebraska-Lincoln, Conservation and Survey Division, 2014) were converted to reference the 

NAVD 88 datum before being included in the TPNRD georeferenced 

database. Near Western Canal, the TPNRD AEM area extends west 

of the TPNRD boundary to partially overlap the SPNRD AEM area 

(fig. 1). The area of overlap includes a 2008 and 2009 AEM block 

flight (fig. 1). For continuity across the TPNRD-SPNRD boundary, 

the BOA picks derived from the 2010 AEM block flight near Western 

Canal were converted to meters above NAVD 88 and included in the 

TPNRD georeferenced database. 

Before the inclusion of BOA picks from the 2010 inverted AEM 

profiles, conversion of the existing BOA contours was necessary. 

The conversion process is described in the following paragraph. 

Lake McConaughy

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Platte

Platte

River

River

North Platte

River

Blue Creek

Otter Creek

keerC mulP

Clear Creek

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Lonergan Creek

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Whitetail Creek

West Birdwood Creek

East Cedar Creek

Lake Creek

Cedar Creek

Whitetail Creek

keerC dnaS

Cure Creek

keerC eruC

South

Platte

River

Red Willow

Creek

NEBRASKA

COLORADO

COLORADO

NEBRASKA

EXPLANATION

Twin Platte Natural Resources District 

airborne electromagnetic survey boundary 

Structure contour—Shows altitude of base of 

aquifer. Dashed where approximately 

located. Contour interval is 20 meters. 

Datum is North American Vertical Datum of 

1988 (NAVD 88)

Structure contour control point—Symbol color 

indicates elevation range, in meters, above 

NAVD 88

840−860, 940−960, 1,040−1,060

860−880, 960−980, 1,060−1,080

880−900, 980−1,000

900−920, 1,000−1,020

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0 5 10 15 20 MILES

0 5 10 15 20 KILOMETERS

Base from National Atlas of the United States, 2014

Universal Transverse Mercator projection, zone 14 north, in meters

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83)

North American Vertical Datum of 1988 (NAVD 88)

Interstate 80

US Route 26

US Route 26

US Route 30

State Route 92

US Route 385

US Route 138

Interstate 76

State Route 61

US Route 30

16 etuoR etatS

Interstate 80

940

Tributary of

Ash Creek

Tributary of

Figure 3. Elevation of the base-of-aquifer surface for parts of the Twin Platte Natural Resources District, 2014.

Preliminary, 20-m (66-ft) contours were generated using the ArcGIS 

tool, Topo to Raster (Esri, 2014), to interpolate the original contour 

surface (Cannia and others, 2006) and produce a raster version of 

that surface. Next, the ArcGIS tool, contour, was used to recontour 

the data using 20-m (66-ft) intervals (Esri, 2012a). The BOA contour 

data also were converted to reference the NAVD 88 datum by using 

CORPSCON, version 6 (U.S. Army Corps of Engineers, 2014). To 

accomplish the datum conversion, a 100-m grid was created using 

the ArcGIS tool, Create Constant Raster (Esri, 2012b). A set of evenly-distributed points (Esri, 2012c) were extracted from the 100-m 

grid and assigned the CORPSCON-calculated datum-conversion 

offset value between vertical datums (U.S. Army Corps of Engineers, 

2014). The offset values were interpolated to produce an elevation-offset surface, which then was used to adjust the initial surface 

generated from the previously contoured BOA surface in feet above 

NGVD 29, (Cannia and others, 2006) to produce a raster dataset with 

elevations stored in meters above NAVD 88.

Once the vertical datum conversion was completed, the process 

of creating new BOA contours (fig. 3) was similar to that done with 

the NPNRD and SPNRD areas. The adjusted (NAVD 88) BOA was 

contoured using a 20-m (66-ft) interval, and this modified version of 

Cannia and others (2006) BOA surface was used as one input for the 

new, refined BOA dataset. The georeferenced dataset of BOA picks 

that included the 2010 inverted AEM profiles was the second input. 

The Topo to Raster tool was used to interpolate the new, updated 

BOA-elevation surface from these two inputs. The new BOA surface was refined to ensure that no grid cells had BOA elevations 

above land surface elevation (10-m DEM). The GIS tool, contour, 

was used to generate a set of preliminary hypsometric contours from 

the refined gridded surface using a contour interval of 20 m (66 ft). 

The generated contours then were manually adjusted based on the 

interpreted location of paleovalleys eroded into the BOA surface and 

associated bedrock highs, many of which were unmapped before this 

study (fig. 3). All GIS datasets for the new BOA surface are included 

at the following link (http://pubs.usgs.gov/sim/3310/GIS_files).

BASE-OF-AQUIFER ELEVATION AND CONFIGURATION

 The contours of the elevation and configuration of the BOA presented in this report (figs. 2 and 3) can be used to identify paleovalleys and associated bedrock highs. When overlain by the water-table 

surface, the aquifer’s saturated thickness can be computed (but is not 

provided herein), which allows an estimate of total water in storage. 

The maps of the BOA surface presented in this report can be used 

as the lower boundary layer in existing and future groundwater-flow 

models. Accurate elevation and configuration of the BOA are essential for improving the accuracy of groundwater-flow models and the 

usefulness of models as tools for understanding groundwater and 

surface-water interaction, and for analyzing water-resources-management alternatives. The integration of geophysical data into the contouring process facilitated a more continuous and spatially comprehensive view of the hydrogeologic framework compared to test-hole 

data alone.

CONVERSION FACTORS

SI to Inch/Pound

Multiply By To obtain

Length

centimeter (cm) 0.3937 inch (in.)

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi)

meter (m) 1.094 yard (yd) 

Area

hectare (ha) 2.471 acre

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit 

(°F) as follows: °F=(1.8×°C)+32

Vertical coordinate information varies and is specific to the Natural Resources 

District being studied. Vertical coordinate information for the North Platte 

Natural Resources District and South Platte Natural Resources District 

is referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29). 

Vertical coordinate information for the Twin Platte Natural Resources District 

is referenced to the North American Vertical Datum of 1988 (NAVD 88). 

Horizontal coordinate information is referenced to the North American Datum 

of 1983 (NAD 83). Altitude, as used in this report, refers to distance above the 

vertical datum.

ACKNOWLEDGMENTS

The authors thank Ronald Cacek and John Berge, managers at 

the North Platte Natural Resources District; Rod Horn, manager at 

the South Platte Natural Resources District; Kent Miller, manager at 

the Twin Platte Natural Resources District; and the Nebraska Environmental Trust, for coordination of support of this study.

REFERENCES CITED

Abraham, J.D., Cannia, J.C., Bedrosian, P.A., Johnson, M.R., Ball, 

L.B., Sibray, S.S., 2012, Airborne electromagnetic mapping of the 

base of aquifer in areas of western Nebraska: U.S. Geological Survey Scientific Investigations Report 2011–5219, 38 p.

Auken E., Viezzoli A., Christensen A.V., 2009, A single software 

for processing, inversion, and presentation of AEM data of different systems—The Aarhus Workbench: ASEG Extended Abstracts 

2009, 5 p., accessed June 2014 at http://www.publish.csiro.

au/?act=view_file&file_id=ASEG2009ab062.pdf.

Bjorklund, L.J., 1957, Geology and ground-water resources of the 

lower Lodgepole Creek drainage basin, Nebraska, with a section 

on The chemical quality of the water, by E.R. Jochens: U.S. Geological Survey Water-Supply Paper 1410, 76 p., 4 pls.

Cannia, J.C., Woodward, D.D., and Cast, L.D., 2006, Cooperative 

Hydrology Study (COHYST) hydrostratigraphic units and aquifer 

characterization report: Lincoln, Nebr., Nebraska Department of 

Natural Resources, 96 p. 

Carney, C.P., 2008, Groundwater flow model of the central model 

unit of the Nebraska Cooperative Hydrology Study (COHYST) 

area: Lincoln, Nebr., Nebraska Department of Natural Resources, 

87 p., accessed February 2013 at http://cohyst.dnr.ne.gov/adobe/

dc012CMU_GFMR_081224.pdf.

Christiansen, A.V., and Auken, E., 2010, A global measure for depth 

of investigation in EM and DC modeling, in ASEG2010 International Geophysical Conference, 21st, 2010, Extended Abstracts: 

Sydney, Australian Society of Exploration Geophysicists, 4 p., 

accessed July 1, 2014 at http://www.publish.csiro.au/paper/ASEG2010ab266.htm.

Darton, N.H., 1903a, Geologic atlas of the United States, Scotts Bluff 

folio, Nebraska: U.S. Geological Survey Folio 88, 5 p.

Darton, N.H., 1903b, Preliminary report on the geology and water 

resources of Nebraska west of the one-hundred and third meridian: 

U.S. Geological Survey Professional Paper 17, 69 p.

Esri, 2012a, ArcGIS Help 10.1—Contour (spatial analyst): Redlands, 

Calif., accessed July 1, 2014, at http://resources.arcgis.com/en/

help/main/10.1/index.html#//009z000000ts000000.

Esri, 2012b, ArcGIS Help 10.1—Create constant raster (spatial analyst): Redlands, Calif., accessed July 1, 2014, at http://resources.

arcgis.com/en/help/main/10.1/index.html#//009z000000s4000000.

Esri, 2012c, ArcGIS Help 10.1—Extract values to points (spatial analyst): Redlands, Calif., accessed July 1, 2014, at http://resources.

arcgis.com/en/help/main/10.1/index.html#//009z0000002t000000.

Esri, 2013, World shaded relief: ArcGIS World Imagery, accessed 

February 25, 2014, at http://goto.arcgisonline.com/maps/World_

Shaded_Relief.

Esri, 2014, ArcGIS—Mapping and spatial analysis for understanding 

our world: Redlands, Calif., accessed January 21, 2014, at http://

www.esri.com/software/arcgis.

Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, 

J.B., 1984, Geohydrology of the High Plains aquifer in parts of 

Colorado, Nebraska, New Mexico, Oklahoma, South Dakota, 

Texas, and Wyoming: U.S. Geological Survey Professional Paper 

1400–B, 63 p.

Hobza, C.M., and Sibray, S.S., 2014, Hydrostratigraphic interpretation of test-hole and borehole geophysical data, Kimball, Cheyenne, and Deuel Counties, Nebraska, 2011–12: U.S. Geological 

Survey Open-File Report 2014–1103, 45 p., [Also available at 

http://pubs.usgs.gov/of/2014/1103/.]

Houston, N.A., Gonzales-Bradford, S.L., Flynn, A.T., Qi, S.L., Peterson, S.M., Stanton, J.S., Ryter, D.W., Sohl, T.L., and Senay, G.B., 

2013, Geodatabase compilation of hydrogeologic, remote sensing, 

and water-budget-component data for the High Plains aquifer, 

2011: U.S. Geological Survey Data Series 777, 12 p., [Also available at http://pubs.usgs.gov/ds/777/.]

Hutchinson, M.F. 1988, Calculation of hydrologically sound digital 

elevation models, in International Symposium on Spatial Data 

Handling, 3d, Sydney, Australia, 1988, Proceedings: Columbus, 

Ohio, The Ohio State University, 421 p.

Hutchinson, M.F. 1989. A new procedure for gridding elevation and 

stream line data with automatic removal of spurious pits: Journal of 

Hydrology, v. 106, p. 211–232.

Hutchinson, M.F., 1996, A locally adaptive approach to the interpolation of digital elevation models, in International conference/workshop on integrating GIS and environmental modeling, 3d, Santa 

Barbara, Calif., 1996, Proceedings: National Center for Geographic 

Information and Analysis, accessed January 2014 at http://www.

ncgia.ucsb.edu/conf/SANTA_FE_CD-ROM/sf_papers/hutchinson_

michael_dem/local.html.

Hutchinson, M.F. and Gallant, J.C., 2000, Digital elevation models 

and representation of terrain shape, in Wilson, J.P., and Gallant, 

J.C., eds., Terrain analysis: New York, Wiley, p. 29–50.

Hutchinson, M.F., Xu, T. and Stein, J.A., 2011, Recent progress in 

the ANUDEM elevation gridding procedure, in Hengel, T., Evans, 

I.S., Wilson, J.P., and Gould, M., eds., Geomorphometry: Redlands, 

Calif., p. 19–22, accessed January 2014 at http://geomorphometry.

org/HutchinsonXu2011.

Luckey, R.R., and Cannia, J.C., 2006, Ground water flow model of 

the western model unit of the Nebraska Cooperative Hydrology 

Study (COHYST) area: Lincoln, Nebr., Nebraska Department of 

Natural Resources, 63 p., accessed May 2013 at http://cohyst.dnr.

ne.gov/adobe/dc012WMU_GFMR_060519.pdf.

National Atlas of the United States, 2014, 1:1,000,000-scale county 

boundaries of the United States: vector digital data, accessed 

July 28, 2014, at http://nationalatlas.gov/atlasftp-1m.html.

National Oceanic and Atmospheric Administration, 2014, Climatological data summary: Asheville, N.C., National Climatic Data 

Center, accessed January 2014 at http://www.ncdc.noaa.gov/cdoweb/results.

Nebraska Department of Natural Resources in work-share agreement 

with the U.S. Geological Survey, 1998, DEM 10 meter index—

7.5 digital elevation models, DEM, 10 meter, index for the State of 

Nebraska: Menlo Park, Calif., U.S. Geological Survey, accessed 

January 20, 2010, at http://dnr.nebraska.gov/dem-10-meter-index.

Peterson, S.M., 2007, Groundwater flow model of the eastern model unit of the Nebraska Cooperative Hydrology Study 

(COHYST) area: Lincoln, Nebr., Nebraska Department of Natural 

Resources, 80 p., [Also available at http://cohyst.dnr.ne.gov/adobe/

dc012EMU_GFMR_090507.pdf.]

Kenny, J.F., 2008, Platte River recovery and implementation program: Kearney, Nebr., Platte River Recover and Implementation 

Program, 3 p., accessed May 2014 at https://www.platteriverprogram.org/News/Documents/PRRIP%20General%20Fact%20Sheet.

pdf.

Qi, S.L., 2010, Digital map of the aquifer boundary of the High 

Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Data Series 543, [Also available at http://pubs.usgs.gov/

ds/543/.]

Qi, S.L., and Christenson, Scott, 2010, Assessing groundwater 

availability in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, 

and Wyoming: U.S. Geological Survey Fact Sheet 2010–3008, 

revised March 2010, 4 p., [Also available at http://pubs.usgs.gov/

fs/2010/3008/.]

Sibray, S.S., and Zhang, Y.K., 1994, Three-dimensional modeling of 

hydraulic behavior of a highly conductive secondary permeability 

zone in the Brule Formation, in Warner, J.W., and Heijde, Paul van 

der, eds., 1994 Groundwater modeling conference, Fort Collins, 

Colo,, 1994, Proceedings: Fort Collins, Colo., Colorado State University, p. 445–452.

Smith, B.D., Abraham, J.D., Cannia, J.C., and Hill, P.L., 2009, Helicopter electromagnetic and magnetic geophysical survey data for 

portions of the North Platte River and Lodgepole Creek, Nebraska, 

June 2008: U.S. Geological Survey Open-File Report 2009–1110, 

27 p. [Also available at http://pubs.usgs.gov/of/2009/1110/.]

Smith, B.D., Abraham, J.D., Cannia, J.C., Minsley, B.J., Deszcz-Pan, 

M., and Ball, L.B., 2010, Helicopter electromagnetic and magnetic 

geophysical survey data, portions of the North Platte and South 

Platte Natural Resources Districts, western Nebraska, May 2009: 

U.S. Geological Survey Open-File Report 2010–1259, 33 p. [Also 

available at http://pubs.usgs.gov/of/2010/1259/.]

Smith, B.D., Grauch, V.J.S., McCafferty, A.E., Smith, D.V., Rodriguez, B.R., Pool, D.R., Deszcz-Pan, M., and Labson, V.F., 2007, 

Airborne electromagnetic and magnetic surveys for ground-water 

resources—A decade of study by the U.S. Geological Survey, in 

Milkereit, B., ed., Exploration 07—Exploration in the new millennium, in Decennial International Conference on Mineral Exploration, 5th, Toronto, 2007, Proceedings: Toronto, Ontario, Decennial 

Mineral Exploration Conferences, p. 895–899.

Smith, F.A., 1969, Preliminary groundwater report—Availability of 

groundwater for irrigation in Cheyenne County, Nebraska: Lincoln, 

Nebr., Nebraska Water Survey, Conservation and Survey Division, 

University of Nebraska-Lincoln, 89 p.

Smith, F.A., and Souders, V.L., 1971, Occurrence of groundwater 

in Kimball County, Nebraska: Lincoln, Nebr., Nebraska Water 

Survey, Conservation and Survey Division, University of Nebraska-Lincoln Water Supply Paper no. 29, 135 p.

Smith, F.A., and Souders, V.L., 1975, Groundwater geology of 

Banner County, Nebraska: Lincoln, Nebr., Nebraska Water Survey, 

Conservation and Survey Division, University of Nebraska-Lincoln 

Water Supply Paper no. 39, 96 p.

 Souders, V.L., 1986, Geologic sections, ground-water maps, and logs 

of test-holes, Morrill County, Nebraska: Lincoln, Nebr., Nebraska 

Water Survey, Conservation and Survey Division, University of 

Nebraska-Lincoln Open-File Report, 90 p.

South Platte Natural Resources District, 2008, Integrated management plan: Sidney, Nebr., and Lincoln, Nebr., South Platte Natural 

Resources District, Nebraska Department of Natural Resources, 

63 p., accessed on January 2014 at http://www.spnrd.org/PDFs/

Rules_Regs_Programs/IMP%20September%2014,%202009.pdf.

Stanton, J.S., Qi, S.L., Ryter, D.W., Falk, S.E., Houston, N.A., 

Peterson, S.M., Westenbroek, S.M., and Christenson, S.C., 2011, 

Selected approaches to estimate water-budget components of the 

High Plains, 1940 through 1949, and 2000 through 2009: U.S. 

Geological Survey Scientific Investigations Report 2011–5183, 

79 p.

Steele, G.V., Sibray, S.S., and Quandt, K.A., 2007, Evaluation of 

ground water near Sidney, western Nebraska, 2004–05: U.S. Geological Survey Scientific Investigations Report 2007–5086, 54 p. 

[Also available at http://pubs.usgs.gov/sir/2007/5086/.]

Swinehart, J.B., Souders, V.L., DeGraw, H.M., and Diffendal, R.F., 

Jr., 1985, Cenozoic paleogeography of western Nebraska, in 

Flores, R.M., and Kaplan, S.S., eds., Cenozoic paleogeography of 

west-central United States: Denver, Colo., Rocky Mountain Section, Society of Economic Paleontologist and Mineralogists, 

p. 209–230.

U.S. Army Corps of Engineers, 2014, Corpscon version 6.0: Topographic Engineering Center, Survey Engineering and Mapping 

Center of Expertise, accessed July 1, 2014, at http://www.agc.army.

mil/Missions/Corpscon.aspx.

U.S. Geological Survey Crustal Geophysics and Geochemistry 

Science Center, 2014, Airborne geophysical surveys conducted in 

western Nebraska, 2010—Contractor reports and data: U.S. Geological Survey Open-File Report 2013–1268, 4 p., http://dx.doi.

org/10.3133/ofr20131268.

 University of Nebraska-Lincoln, Conservation and Survey Division, 2014, Nebraska statewide test-hole database: Lincoln, Nebr., 

Conservation and Survey Division, accessed January 21, 2014, at 

http://snr.unl.edu/data/geologysoils/NebraskaTestHole/NebraskaTestHoleIntro.asp.

Wenzel, L.K., Cady, R.C., and Waite, H.A., 1946, Geology and 

ground-water resources of Scotts Bluff County, Nebraska: U.S. 

Geological Survey Water-Supply Paper 943, 150 p.

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Map 3310

Sheet 2 of 2

Prepared in cooperation with the 

North Platte Natural Resources District, South Platte Natural Resources District, Twin Platte Natural Resources District, Conservation and Survey Division of the University of Nebraska-Lincoln, and the Nebraska Environmental Trust

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not 

imply endorsement by the U.S. Government.

This map was printed on an electronic plotter directly from digital files. Dimensional calibration may vary 

between electronic plotters and between X and Y directions on the same plotter, and paper may change 

size due to atmospheric conditions; therefore, scale and proportions may not be true on plots of this map.

For more information on the USGS—the Federal source for science about the Earth, its natural and living 

resources, natural hazards, and the environment—visit http://www.usgs.gov or call 1–888–ASK–USGS 

This report is available at http://dx.doi.org/10.3133/sim3310.

Suggested Citation: Hobza, C.M., Abraham, J.D., Cannia, J.C., Johnson, M.R., and Sibray, S.S., 2014, Base 

of principal aquifer for parts of the North Platte, South Platte, and Twin Platte Natural Resources Districts, 

western Nebraska: U.S. Geological Survey Scientific Investigations Map 3310, 2 sheets, http://dx.doi.

org/10.3133/sim3310. ISSN 2329-132X (online)