800 
 1950 1955 1965 970 
 
 
Figure 1 —Value of natural gas, petroleum, and total value of mineral
production in 
Oklahoma. 
648 MINERALS YEARBOOK, 1967 
 1,200 
 
 
 
 
 
 
1,000 
 
 
 
 
 
 
 
 
 
 
 
U, 
 
0 
 
~ 600 
 
C 
0 
 
 
E 
w 
 
400 
 
 
 
 
 
 
200