328 W. H. WEED — TWO MONTANA COAL FIELDS. 



The fourth and fifth seams show the structure indicated in the dia- 

 gram. The sections of seam number iv do not, of course, give the entire 

 width of the seam, but only the portion worked. The roof is a firm sand- 

 stone, so that only the main entry, 18 feet wide, is timbered, and the slope 

 the same. The seam is opened by a half mile of entry and a slope of 

 GOO feet. These workings show the seam to have a dip of 18° at outcrop 

 and 16° at the bottom of the slope, the roof being very constant. The 

 floor is a soft gray shale having a slight roll. The lower partings of the 

 seam are very constant, but the uppermost parting is quite variable in 

 thickness. The seam has a nearly uniform thickness of 12 feet, of which 

 20 inches is left to form the roof over the rooms. The roof of this seam 

 rolls considerably. 



A 5-foot seam of coal lies between seams number iv and v, with 35 feet 

 of rock between it and number iv ; but the seam has too many partings 

 to be workable. 



Number v is but little worked, the mine being abandoned on account 

 of the partings and the prevention of economical working by the bottom 

 coal. The roof rolls but very little, not so much as number iv. The coal 

 above the 30-inch bench is all one bench, or has but thin partings, of no 

 consequence farther in. 



Seam number vi is 5 to 6 feet thick and shows a clean bench of coal 

 having only one parting of an inch in thickness about midway. The 

 coal is bright and breaks into prismatic masses with hackly fracture. 

 The roof rolls in strong waves and the floor also rolls. No timbering is 

 done in the entries of seams numbers v and vi, but though the roof of 

 number vi is a hard sandstone it is crushing in the rooms and is held up 

 by timber cribs. 



While the seams numbers i, iii and v are not mined at present, owing 

 to the greater profit of mining the other seams, they are valuable for 

 future supply. 



The Rocky Fork Coal company holds 3,440 acres of property, being a 

 strip about two miles wide (the entire width of the outcropping seams of 

 the field) and some three miles long, comprising the high benchland and 

 broken country about the head of Bear creek, east of Rocky Fork creek. 

 To the eastward the seams flatten out to a dip of 5°, with low arching 

 of the beds. 



Bear Creek Mine*. — In this eastward extension of the field the area 

 available for mining has a much -greater width, as the beds flatten out 

 gradually toward Clarkes fork. In general the trend of the field is toward 

 the southeast. Numerous locations have been made and short prospect 

 entries driven on the seams that outcrop in the sides of the gulches. The 

 most extensive working has been made by agents of Butte capitalists, 



