COAL  IN  NORTH  WESTERN  COLORADO  AND  NORTHEASTERN  UTAH.   299 
AREA  NORTH  OF  THE  BASE  LINE. 
General  section  of  Mesaverde  formation. — As  the  rocks  of  the  lower 
White  River  field  form  a  direct  westward  continuation  of  the  outcrops 
of  the  same  formations  that  are  exposed  in  and  adjacent  to  the  Dan- 
forth  Hills,  no  sharp  distinction  nor  marked  variation  in  the  beds  of 
the  two  fields  is  to  be  noted.  As  explained  more  in  detail  in  the 
discussion  of  the  Vernal  field,  the  Mesaverde  appears  to  become 
thinner  as  traced  toward  the  west,  being  in  the  vicinity  of  Red  Wash 
only  2,500  feet  thick,  or  half  the  thickness  exposed  on  White  River 
near  Meeker.  This  thinning  is  thought  to  be  due  to  the  fact  that 
erosion  of  a  former  land  surface  had  progressed  to  a  considerable 
depth  into  those  beds  before  the  succeeding  Tertiary  strata  were  laid 
down  upon  them. 
Total  amount  of  coal  in  the  Mesaverde  section. — As  explained  in  the 
published  report  on  the  Danforth  Hills  coal  field,  the  only  available 
section  where  satisfactory  measurements  of  the  total  amount  of  coal 
in  the  Mesaverde  formation  can  now  be  had  is  that  exposed  on  White 
River  a  few  miles  below  Meeker.  Here  at  least  73  feet  in  ten  beds, 
each  of  workable  thickness,  was  well  enough  opened  by  development 
so  that  the  coal  could  be  measured.  It  is  thought  likely  that  a  com- 
plete measurement  at  that  place  would  show  even  more  coal  than  this. 
Unfortunately  the  scattered  prospects  and  small  amount  of  develop- 
ment in  the  lower  White  River  field  do  not  permit  even  a  fair  estimate 
of  the  total  amount  of  coal.  To  judge  from  the  few  exposures  avail- 
able, and  from  such  general  indications  as  natural  exposures  of  coal 
smut  and  the  relative  intensity  of  baking  where  coal  beds  have  been 
burned  in  outcrops,  the  distribution  of  the  groups  of  coal  beds  is 
thought  to  be  very  similar  to  that  of  the  Danforth  Hills.  Owing  to 
the  thinning  of  the  coal-bearing  formation  toward  the  west,  thought 
to  be  caused  by  the  absence  of  its  upper  members,  it  seems  likely 
that  the  upper  coal  group  of  the  Danforth  Hills  may  be  partly  lacking 
west  of  Coyote  Basin,  and  it  is  almost  certainly  absent  a  short  dis- 
tance west  of  the  mouth  of  Wolf  Creek. 
An  additional  and  probably  still  more  important  factor  influencing 
the  total  amount  of  available  coal  in  the  lower  White  River  field  is 
an  apparently  local  decrease  in  the  thickness  and  number  of  workable 
beds  in  the  part  of  the  formation  exposed  between  the  district  at  the 
mouths  of  Wolf  and  Yellow  creeks  and  a  district  just  west  and  south 
of  the  mouth  of  Red  Wash.  Here,  in  spite  of  relatively  more  active 
local  demand  for  fuel  supply  in  the  adjacent  valley  of  White  River, 
but  few  important  coal  beds  seem  to  have  been  discovered,  and  sev- 
eral that  are  of  workable  thickness  are  badly  broken  by  layers  of  shale 
or  bone.  With  the  possibility  that  valuable  beds  will  still  be  discov- 
ered in  this  vicinity,  it  seems  very  likely,  nevertheless,  that  the  total 
