330  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1905 
Besides  the  larger  mines  on  or  near  the  railroads  there  are  hundreds  of  localities  all  over 
the  area  where  lignite  is  mined  on  a  larger  or  smaller  scale.  Throughout  the  greater  por- 
tion of  the  area  lignite  is  the  only  fuel  used,  and  the  ranchmen  occasionally  haul  it  10  or 
15  miles.  Usually,  however,  there  is  a  scam  near  by  from  which  a  supply  may  he  obtained. 
It  is  generally  taken  from  some  outcrop  where  it  can  he  gotten  with  the  least  amount  of 
labor.  When  the  seam  lies  near  the  surface  the  lignite  is  reached  by  stripping,  or  if  it  is 
exposed  in  a  cut  bank  or  steep  bind'  it  is  removed  from  the  face  of  the  outcrop  with  the 
pick  or  by  blasting. 
With  few  exceptions,  the  roof  over  the  lignite  is  clay  or  sometimes  soft  sandstone,  and 
timbering  is  necessary,  at  least  in  the  entries.  But  where  the  seam  is  thick  enough  6 
inches  to  '2  feet  of  lignite  is  left,  and  this  usually  makes  a  safe  roof,  which  may  require  no 
supports. 
