, 1924-05-15

Inc IollOWluS dfJlcle WrlCt
geologist, and published in the
great interest to many readers
The region to be discussed
cifc railroad from Laramie to
mately 25 structures, mainly in
The geology of this territory /
logical Survey Bulletins No. 81
1O8, Geological Folio 173, and
tions of the State Geologist relating
to the area Press Bulletins No. 4,
No. Z. and No. ~. which are now
out of print. Recent discoveries Of
oil in the Rex Dome, Simpson Ridge,
and Medicine Bow structures have
aroused considerable interest In the
entire area and have created a de-
mand for information regarding de-
v~elopments.
The Rock Creek field is one of the
most important producing fields in
Wymoing; the fields recently dis
covered may become important;
some structures have not yet been
fully tested, while others have been
proven to be barren. 1t is the in
tention of this bulletin to v
briefly the results Of the various
tests, with a short discussion of the
geology.
In a number of cases the wells
were drilled several years ago, the
wells abandoned, and the operators
have left. The law requiring oper-
ators on patented Or state land to
file logs and reports in the Office OF
the State Geologist was not passed
until 1921, consequently it is almost
impossible to secure a complete and
accurate record Of all the tests in
this area, but the information given
herein is believed to be as accurate
as is obtainable at this time.
The State Geologist has for free
distribution a limited number of
copies Of a map showing the loca-
ton of oil structures on which can
be found the structures mentioned
in this bulletin.
Big Hollow
The Big Hollow Anticline in a
north and south trending anticline
mainly along the west side OF Town
ship Is n. Range rs W., and
plunges to- the north. the surface for
nation being the Niobrara. In the
eastern part OF the same township
and in the northwestern part of
Township Is N, Range "a w, evil
dences of an anticline have been
found and have led to drilling.
The Wyoming Spindletop Oil Co.
drilled in the swk sec. ~32-16n-74w
to a depth OF 1900 1t; a little dead
oil was found in the first sand at
700 It. and some gas at 100 1t. The
Briggs Oil Syndicate started a well
May /, 1922, on the swK OF section
~32-16-74, which at this time is drill
ing at a depth OF 3075 It. with blue
shale at 3O4O. The surface rocks be-
long to the Niobrara; the Muddy.
Dakota and Lakota were tested, the
Muddy being dry. the Dakota water
bearing. At 1895 IT. in the Morri-
son a heavy gas pressure was en-
countered. In the Chugwater. red
shale was found from 211O to 294O
IT,. with limestone beneath.
In sec. 1%2-15-75. the Reasoning
Oil Co. abandoned its well in the
SELL sek a a depth Of 1440 It,.
water being found in both the Muddy
and Cioverly sands. The Stefin
Syndicate drilled In the swA of the
same section, going thru the Frontier
sands At 4SO IT,. with no Oil show
Ing, q comparison OF the logs of the
two wells indicating that this well Ia
from so to so feet higher on the
structure.
A number of shallow wells drilled
several years & in the south a
of section 6-15-75 indicates h poss-
ibility OF small production Of heavy
oil from the Harris sand at about
800 feet. but on ccount OF qualit,