}os

<sa

^ml

Ta

Jmi

<gn

Tlg

Tvs

Jm

Jmi

<gn

}os

TKm

KJlg

Jmi

Tvs

Jmi

KJlg

Tsy

KJlg

TKm

Tgr

}os

}os

}os

}os

}os

}os

}os

Tsy

Tqp

Tpd

Tqp

Tqp

}os

Tsy

Qoam

Tqd

}os

Jmi

Jmi

Jmi

Jmi

Jmi

Jmi

Jmi

Jmi

Jmi

Jmi

Jmi

TKm

Tqp

Tqp

KJbg

Jmi

Jm

Jmi

Jmi

Jmi

Jmi

Jmi

Jmi

Jmi

Jmi

KJlg

TKm

KJog TKm

KJog

Tso

Jmi

Jmi

Jmi

Jmi

Jmi

Jm

Jm

Jm

Jm

Jm

Jm

Tsy

Jm

Tsy

KJbg

KJlg

KJog

KJbg

KJbg

KJbg

KJbg

KJbg

KJbg

KJbg

KJlg

KJlg

Jmi

KJlg

KJlg

KJbg

Jmi

Jm

Jm

Jw KJlg

KJlg

KJlg

KJlg

KJlg

KJlg

Jmi

KJlg

KJlg

KJog

KJog

KJog }osg

KJog

KJog

KJog

KJog

KJog

KJog

KJog

}os

KJog

KJog

KJog

KJbg

KJog

KJog

}<gn

}<gn

<gn

<gn

<gn

<gn

<gn

TKm

Trfp

Td

Tfpi

Tlg

<gn

^ml

Ql

Ql

Ql

Ql

<gn

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qya Qya

Qya

Qya

Qya

Ta

Jmi

Tvs

Td

Tfpi

Jmi

Tqp

Tlg

Tlg

Qoau

}os

Tvs

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qya

Qoau

Jmi

Tgr

TKm

TKm

TKm

^ml

^ml

^ml

Tb

Tb

Tvs

<gn

<gn Tlg

Tso Tso

Tso

Tvs

Tfpi

Tvs

Td

Tvs

Jmi

<gn

Tqp

Tsy Tsy

Tvs

Tvs

Tvs

Tvs

Tvs Tvs

Jmi

Tvs

Tlg

Tvs

Tgr

Jmi

Tlg

<gn

Tvs

Tvs

Tvs

Tvs

Tgr

Tvs

Tvs

Tvs

Tvs

Tvs

Tlg

Qya

Qya

Jm

Tqd

Tfpi

Tfpi

Tfpi

Tfpi

Tfpi

Tfpi

Tfpi

Tfpi

Tpu

Tpu

Tfpi

KJlg

KJlg

Qoau

Jmi

Qoau

Tgr

Tgr

Tqd

Tqd

Tgr

Tgr

Tgr

Tgr

Tmg

Tgr

Tgr Tqd

Tgr

Tgr

Tgr

Tmg

Tgr

Tgr

Tgr

Tsy

Tlg

Tgr

Tgr

Tgr

Tgr

Tlg

Tlg

Tlg

Tlg

Tlg

Tlg

Tlg

Tlg

Tlg

Tlg

Tlg

Tlg

Tlg

Tmg

Tmg

Tmg Tmg

Tmge

Tmgp

Tmgp

Tmgp

Tmgp

Tpu

Tpu

Tpu

Tpu

Tpu

Tpmgu

Tpmgu

Tpd

Tqd

Tqd

Tqd

Tqd

Tqd

Tqd

Tqd

Tqd

Tqd

Tqd

Tqd

}os

Tqd

Tqd

Tqd

Tqd

Tqd

Tqp

Tqp

Tqp

Qya

Qya

Qya

Qya

KJbg

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoau

Qoam Qoam

Qoam

Qoam

Qoam

Qoam

Qoam

Qoam

Qoam

Qoam

Qoam

Qoam

Qoam

Tsy Tsy

Tsy

Qoam

}osg

Tqp

Tqd

Jmi

Qoam

<gn

Tfpi

Tqp

Tfpi

Tfpi

Tlg

Tqp

Tqp Tqp

Tso

Qoau

Tqd

Tqd Tqd

Qoam

<gn

<gn

<gn

Jmi

Tlg

Qoau

Tqd

Tqd

Tqd

Tqd

Tqd Qoam

}osqm Tqp

Qoau

Tvs

Tsy

Tsy

Tqp

Tso

Tso

KJlg

Qoam

Tvs

^ml

}<gn

^ml

}osg

Qoau

Tqp

Trfp

Trfp Trfp

Trfp

KJbg

Tso

Tsy

Tqp

}osg

}osg

}osqm

}<gn

}osqm

Jmi

Tpd

}osg

Tqp Tqp Tvs

Td

}osqm

KJlg Tvs

}osg }osg

}osqm

KJlg

Jmi

Qe

Ql

Qoau

KJbg

Trfp

}osg

Tso

Trfp

Qoau

Tqp

Qoam

Tvs

Tfpi

Tqp

Ql

Ql

Tpmgu

Tpmgu

Tlg

Tlg

Tfpi

Qya

}os

Qoam

^ml

<gn

Jmi

^ml

Jmi

Tmge

Tmge

Tmgp

Tqd

Tgr

Qoam

Tgr

Qoam

Tfpi

Tvs

Jmi

Jmi

Tlg

Tvs

Tlg

Tvs

Qoam

Qoau

Tgr

Tgr

Tgr

Tgr

Tqd

Tmg

Tmgp

Jm

Tfpi

Tfpi

Tlg

Tvs

}os

KJlg

^ml

Jmi

Qoam

}osg

U U D D

U

D

U

D

U

D

U

D

U

D

U

D

U

D

Geologic Map and Database of the Chocolate Mountain Aerial Gunnery Range, Riverside and Imperial Counties, California

By

2018

CONTOUR INTERVAL 50 METERS

1927 NORTH AMERICAN DATUM

1 10 KILOMETERS

SCALE 1:100 000

1 0 1 2 3 4 5 6 7 8 MILES

APPROXIMATE MEAN

DECLINATION, 2018 

11°

Base from U. S. Geological Survey, 1981 Universal Transverse Mercator projection

Custom image and extent prepared by ChartTiff; www.ChartTiff.com: fonts and colors

were assigned by ChartTiff in their custom preparation of this raster product and were 

retained in the reference base for expediency. 

10,000-meter grid based on California coordinate system, zone 11

25,000-foot ticks based on California coordinate system, zone 5

MAGNETIC 

NORTH

TRUE NORTH

CALIF

MAP LOCATION

Robert E. Powell, Robert J. Fleck, and Pamela M. Cossette ISSN 2331-1258

https://doi.org/10.3133/ofr2018-xxxx

1 65432 987

Geology mapped and compiled by Robert E. Powell, 1993-2017,

John T. Dillon, 1976, and Robert J. Fleck, 2008-2017

Digital database and cartography by Pamela M. Cossette, 2017

Initial digital conversion by Gary Patt, 1994

Edited by Claire Landowski,

Menlo Park Publishing Service Center

Manuscript approved for publication December 11, 2018

Any use of trade, product, or firm names is for descriptive 

purposes only and does not imply endorsement by the 

U.S. Government

This map or plate is offered as an online-only, digital 

publication. Users should be aware that, because of 

differences in rendering processes and pixel resolution, some 

slight distortion of scale may occur when viewing it on a 

computer screen or when printing it on an electronic plotter, 

even when it is viewed or printed at its intended publication 

scale

Suggested citation: Powell, R.E., Fleck, R.J., and Cossette, P.M., 

2018, Geologic map and database of the Chocolate Mountain 

Aerial Gunnery Range, Riverside and Imperial Counties, 

California: U.S. Geological Survey Open-File Report 2018-1191, 2 

sheets, scale 1:100,000, https://doi.org/10.3133/ofr20181191.

Digital files are available at https://doi.org/10.3133/ofr20181191

Open File Report 2018–1191 

Sheet 1 of 2

Prepared in cooperation with the

U.S. Navy and U.S. Marine Corps

U.S. Department of the Interior

U.S. Geological Survey