NORTH    DAKOTA -MONT  AN  A    LIGNITE    AREA.  325 
In  that  part  of  the  valley  of  the  Little  Missouri  which  has  an  east-west  course  for  many 
miles  a  13-foot  seam  is  exposed  not  far  from  the  mouth  of  Deep  Creek.  Many  lignite 
seams  occur  above  this  point  in  the  vicinity  of  Yule.  In  the  river  bluffs  about  2  miles 
below  the  post-office,  on  the  east  side  of  the  valley,  three  seams  are  present,  as  shown  in 
the  following  generalized  section: 
Generalized  section  2  miles  below  Yule. 
Feet. 
Clay  and  sand 4-50 
Lignite •      8-  10 
Clay  and  soft  sandstone 35 
Lignite 7-    8 
Clay  and  sand 100 
Sandstone  ledge 1 
Lignite 8 
Clay,  to  river  level 30 
The  lower  seam  outcrops  at  several  points  in  the  cut  banks  on  both  sides  of  the  river 
for  a  distance  of  2  or  3  miles.  The  two  upper  seams  are  exposed  in  the  badlands  border- 
ing the  valley  on  the  east.  Along  the  river  above  Yule  a  10-foot  seam  of  lignite  occurs 
near  water  level  and  can  be  traced  for  several  miles.  It  has  been  mined  and  used  by  those 
living  in  the  vicinity,  but  can  not  be  reached  except  in  winter,  when  the  river  is  frozen. 
Above  this  bed  there  are  two  others  2\  and  3  feet  thick,  respectively.  A  second  10-foot 
seam  is  exposed  near  the  top  of  the  bluff  1  mile  south  of  Yule,  on  the  west  side  of  the  valley. 
Two  and  one-half  miles  southwest  of  the  place  just  described  another  bed  of  lignite  10  feet 
thick  occurs  at  the  mouth  of  Deer  Creek,  at  an  elevation  of  55  feet  above  the  river.  This 
seam  outcrops  at  various  points  for  a  mile  or  more  along  the  valley  of  the  creek.  In  a 
ravine  entering  Little  Missouri  Valley  2  miles  above  the  mouth  of  Deer  Creek,  in  sec.  16, 
T.  135  N.,  R.  105  W.,  six  seams  are  exposed  within  a  vertical  distance  of  165  feet,  as  follows: 
Lignite  beds  2  miles  above  mouth  of  Deer  Creek. 
Feet. 
160  feet  above  the  river 8-9 
110  feet  above  the  river 3 
85  feet  above  the  river l-£ 
80  feet  above  the  river 4 
58  feet  above  the  river 10 
44  feet  above  the  river 6 
On  Cash  Creek,  which  enters  the  Little  Missouri  from  the  east  about  12  miles  above  Yule, 
a  lignite  seam  8  feet  thick  is  exposed  near  the  J.  S.  Blue  ranch. 
Lignite  occurs  on  Bacon  Creek,  a  tributary  which  flows  eastward  near  the  southern  bor- 
der of  Billings  County.  A  seam  with  a  thickness  of  at  least  29  feet  is  mined  at  the  T-Cross 
ranch  about  7  miles  above  the  mouth  of  the  creek.  The  lignite  outcrops  in  the  side  of  the 
valley  near  the  ranch  buildings  and  is  overlain  by  8  to  10  feet  of  clay.  The  bottom  of  the 
seam  is  not  exposed,  and  the  thickness  given  above  is  only  that  portion  which  lies  above 
the  bed  of  the  stream.  Eight  miles  to  the  southeast,  in  Bowman  County,  another  thick 
seam  occurs  at  the  Dukorn  &  Gamble  ranch  on  Coyote  Creek.  The  entire  thickness  could 
not  be  measured,  since  the  bottom  was  concealed  by  talus,  but  12  feet  of  lignite  are  exposed. 
In  Bowman  County  the  bluffs  bordering  the  Little  Missouri  rise  only  about  80  feet  above 
the  river  and  are  for  the  most  part  covered  with  vegetation.  Outcrops  are  therefore  scarce, 
but  where  the  river  has  cut  into  the  bluff,  forming  steep,  bare  cliffs,  no  lignite  seams  occur. 
From  the  data  at  hand  it  seems  that  there  is  little  or  no  lignite  along  the  river  in  this  county. 
Lignite  along  the  valley  of  Little  Missouri  River  between  Medora  and  Missouri  River. — 
Throughout  this  region  the  beds  are  so  nearly  horrizontal  that  the  river  channel  falls 
continually  lower  with  respect  to  particular  horizons  as  it  extends  to  the  north.  In  the 
vicinity  of  Medora  the  bluffs  are  from  200  to  300  feet  high,  while  north  of  the  Killdeer 
Mountains  the  level  of  the  upland  plain  is  between  500  and  600  feet  above  the  river.     On 
