3. 1997 Demonstrated Reserve Base
and Estimated Recoverable Reserves

Demonstrated Reserve Base

The demonstrated reserve base (DRB) of coal in the United States as of January 1, 1997, contains an estimated 508 billion short tons (Table 6). This is an increase of 12 billion short tons over the previous (January 1, 1995) DRB estimate of 496 billion short tons.⁽¹⁾ The increase is attributable to updated coal resource data from the second phase of EIA's Coal Reserves Data Base (CRDB) project in Illinois (+ 15 billion short tons) and adjustments for the effects of resource depletion (- 3 billion short tons).

Not all the coal in the DRB is recoverable. EIA's latest estimates of the recoverable portions of the DRB indicate that about 54 percent of the national DRB estimate may be recovered by mining.

The DRB includes coal from States in all geographic regions. Nearly half the DRB is found in the Western Coal-Producing Region (Table 7). Coal resources believed to be minable by surface mining make up nearly one-third of the DRB, the major part of which (58 percent) occurs in the West. On the other hand, more than two-thirds of the DRB may be recoverable only by underground mining, and more than half of that amount (58 percent) is found in the Interior and Appalachian Coal-Producing Regions.
 

Table 6. Demonstrated Reserve Base of Coal in the United States, 1995, 1997 (Million Short Tons)
Area and Potential Method of Mining	Anthracite		Bituminous		Subbituminous		Lignite		Total
	1997	1995	1997	1995	1997	1995	1997	1995	1997	1995
States East of the Mississippi	7,345.0	7,350.7	234,728.1	221,345.6	0.0	0.0	1,083.0	1,083.0	243,156.1	229,779.3
Underground Minable	3,975.0	3,975.9	188,964.0	175,553.2	0.0	0.0	0.0	0.0	192,939.0	179,529.1
Surface Minable	3,370.0	3,374.9	45,764.1	45,792.3	0.0	0.0	1,083.0	1,083.0	50,217.1	50,250.2
States West of the Mississippi	131.9	131.9	36,181.8	36,434.0	185,118.0	185,950.4	43,151.9	43,370.1	264,583.5	265,886.4
Underground Minable	116.4	116.4	27,337.1	27,518.1	121,382.6	121,388.8	0.0	0.0	148,836.1	149,023.3
Surface Minable	15.5	15.5	8,844.6	8,915.9	63,735.4	64,561.7	43,151.9	43,370.1	115,747.4	116,863.1
U.S. Total	7,476.9	7,482.6	270,909.9	257,779.6	185,118.0	185,950.4	44,234.9	44,453.1	507,739.6	495,665.7
Underground Minable	4,091.4	4,092.3	216,301.1	203,071.3	121,382.6	121,388.8	0.0	0.0	341,775.2	328,552.4
Surface Minable	3,385.4	3,390.4	54,608.8	54,708.3	63,735.4	64,561.7	44,234.9	44,453.1	165,964.4	167,113.3
Note: Totals based on available data. Totals may not equal sum of components because of independent rounding. Data are reported as of the first day of the year.    Sources: EIA Coal Reserves Data Base program, State geological and mineral resource surveys, and other geological reports.

 

Table 7. Demonstrated Reserve Base of Coal by State and Rank, 1995, 1997 (Million Short Tons)
Coal Producing State and Region	Anthracite		Bituminous		Subbituminous		Lignite		Total
	1997	1995	1997	1995	1997	1995	1997	1995	1997	1995
Alabama	0.0	0.0	3,463.6	3,552.0	0.0	0.0	1,083.0	1,083.0	4,546.6	4,635.0
Alaska	0.0	0.0	697.5	697.5	5,414.4	5,418.4	14.0	14.0	6,125.9	6,129.9
Arizona	0.0	0.0	160.8	188.8	0.0	0.0	0.0	0.0	160.8	188.8
Arkansas	104.1	104.1	287.5	287.5	0.0	0.0	25.4	25.4	416.9	417.0
Colorado	25.5	25.5	8,710.9	8,776.6	3,829.6	3,851.8	4,189.9	4,189.9	16,755.9	16,843.8
Georgia	0.0	0.0	3.6	3.6	0.0	0.0	0.0	0.0	3.6	3.6
Idaho	0.0	0.0	4.4	4.4	0.0	0.0	0.0	0.0	4.4	4.4
Illinois	0.0	0.0	105,068.9	89,956.0	0.0	0.0	0.0	0.0	105,068.9	89,956.0
Indiana	0.0	0.0	9,916.5	9,991.0	0.0	0.0	0.0	0.0	9,916.5	9,991.0
Iowa	0.0	0.0	2,189.5	2,189.5	0.0	0.0	0.0	0.0	2,189.5	2,189.5
Kansas	0.0	0.0	975.0	975.6	0.0	0.0	0.0	0.0	975.0	975.6
Kentucky Total	0.0	0.0	32,040.6	32,564.7	0.0	0.0	0.0	0.0	32,040.6	32,564.7
Kentucky, Eastern	0.0	0.0	12,086.2	12,484.8	0.0	0.0	0.0	0.0	12,086.2	12,484.8
Kentucky, Western	0.0	0.0	19,954.4	20,079.8	0.0	0.0	0.0	0.0	19,954.4	20,079.8
Louisiana	0.0	0.0	0.0	0.0	0.0	0.0	462.7	471.3	462.7	471.3
Maryland	0.0	0.0	717.0	731.4	0.0	0.0	0.0	0.0	717.0	731.4
Michigan	0.0	0.0	127.7	127.7	0.0	0.0	0.0	0.0	127.7	127.7
Missouri	0.0	0.0	5,994.1	5,995.7	0.0	0.0	0.0	0.0	5,994.1	5,995.7
Montana	0.0	0.0	1,385.4	1,385.4	102,531.3	102,627.4	15,759.8	15,760.5	119,676.5	119,773.3
New Mexico	2.3	2.3	3,706.2	3,740.7	8,774.2	8,803.8	0.0	0.0	12,482.7	12,546.8
North Carolina	0.0	0.0	10.7	10.7	0.0	0.0	0.0	0.0	10.7	10.7
North Dakota	0.0	0.0	0.0	0.0	0.0	0.0	9,395.0	9,470.0	9,395.0	9,470.0
Ohio	0.0	0.0	23,663.9	23,754.0	0.0	0.0	0.0	0.0	23,663.9	23,754.0
Oklahoma	0.0	0.0	1,575.0	1,579.6	0.0	0.0	0.0	0.0	1,575.0	1,579.6
Oregon	0.0	0.0	0.0	0.0	17.5	17.5	0.0	0.0	17.5	17.5
Pennsylvania Total	7,219.5	7,225.2	21,426.6	21,642.6	0.0	0.0	0.0	0.0	28,646.1	28,867.8
Anthracite	7,219.5	7,225.2	0.0	0.0	0.0	0.0	0.0	0.0	7,219.5	7,225.2
Bituminous	0.0	0.0	21,426.6	21,642.6	0.0	0.0	0.0	0.0	21,426.6	21,642.6
South Dakota	0.0	0.0	0.0	0.0	0.0	0.0	366.1	366.1	366.1	366.1
Tennessee	0.0	0.0	815.7	827.1	0.0	0.0	0.0	0.0	815.7	827.1
Texas	0.0	0.0	0.0	0.0	0.0	0.0	12,931.0	13,064.9	12,931.0	13,064.9
Utah	0.0	0.0	5,849.3	5,954.6	1.1	1.1	0.0	0.0	5,850.4	5,955.7
Virginia	125.5	125.5	2,076.5	2,201.8	0.0	0.0	0.0	0.0	2,202.0	2,327.3
Washington	0.0	0.0	303.7	303.7	1,077.9	1,089.2	8.1	8.1	1,389.7	1,400.9
West Virginia	0.0	0.0	35,397.1	35,983.1	0.0	0.0	0.0	0.0	35,397.1	35,983.1
Wyoming	0.0	0.0	4,342.5	4,354.4	63,471.9	64,141.4	0.0	0.0	67,814.5	68,495.8
Appalachian Total	7,345.0	7,350.7	99,660.8	101,191.1	0.0	0.0	1,083.0	1,083.0	108,088.8	109,624.8
Interior Total	104.1	104.1	146,088.3	131,182.3	0.0	0.0	13,419.0	13,561.6	159,611.4	144,848.0
Western Total	27.8	27.8	25,160.8	25,406.2	185,118.0	185,950.4	29,732.8	29,808.5	240,039.5	241,193.0
East of the Mississippi	7,345.0	7,350.7	234,728.1	221,345.6	0.0	0.0	1,083.0	1,083.0	243,156.1	229,779.3
West of the Mississippi	131.9	131.9	36,181.8	36,434.0	185,118.0	185,950.4	43,151.9	43,370.1	264,583.5	265,886.4
U.S. Total	7,476.9	7,482.6	270,909.9	257,779.6	185,118.0	185,950.4	44,234.9	44,453.1	507,739.7	495,665.7
1For a definition of coal-producing regions, see Table 13.    Note: Totals based on available data. Totals may not equal sum of components because of independent rounding. Data are reported as of the first day of the year.    Sources: EIA Coal Reserves Data Base program, State geological and mineral resource surveys, and other geological reports.

Coal rank is a measure of the degree of physical alteration, or "maturation" of the organic matter composing the coal. Coal ranks are related in a generalized way to coal heating values. Heat values increase from the lowest rank, lignite, toward the highest rank, anthracite, with the highest heat values found in the low-volatile bituminous coals, just below anthracite in rank. Fifty-three percent of the DRB is comprised of bituminous coals, which are found primarily in the Interior and Appalachian Regions. Subbituminous coals account for more than 36 percent of the total and is all located in the Western States. Lignite makes up less than 9 percent of the DRB, primarily located in the West. Anthracite represents only 1.5 percent of the DRB and almost all of it is located in northeastern Pennsylvania.

DRB summary data by State, coal rank, and potential mining method are presented in Tables 7 through 10, along with the previous (January 1, 1995) DRB for comparison. With the exception of Illinois, the 1997 DRB is based on the same data sources used for the previous DRB. All data are updated to the current base year to account for the estimated effects of resource depletion due to mining and coal lost in the mining process.

The sulfur content of the coal in the DRB has been estimated by EIA according to six ranges of pounds of sulfur per million Btu and five ranges of heat value, in millions of Btu per short ton (Table A1). For more general discussion, however, EIA refers to three major sulfur ranges: low, medium, and high (Table 11). Although no single sulfur range prevails for coal in the United States, there is more high-sulfur coal currently in the DRB than any other range (Table 12). High-sulfur coal makes up 196.9 billion short tons, or 39 percent of all coal included in the DRB. Medium-sulfur coal totals 140.9 billion short tons, or 28 percent of the DRB, and low-sulfur coal amounts to 169.9 billion short tons, or 33 percent.

When examined at the regional level, the distribution of sulfur ranges in coal is much less equally divided. Most of the low-sulfur coal included in the DRB (84 percent) is in the West. Appalachia encompasses 15 percent of the low-sulfur DRB and the Interior only 1 percent (2 billion short tons of low-sulfur resources), located entirely in Illinois, Oklahoma, and Indiana. Similarly, an estimated 87 billion short tons (61 percent) of the medium-sulfur DRB coal is in the West, about 27 percent of the total is estimated to be in Appalachia, and only 13 percent is in the Interior Region. Most of the high-sulfur DRB is in the Interior Region. EIA estimates that the Interior contains nearly 71 percent of the total high-sulfur DRB coal in the United States; Appalachia, less than 23 percent; and the West, 6 percent.

In regard to overall quantities of coal, the smallest share now belongs to the Appalachian Region, with 108 billion short tons, or 21 percent of the DRB. Coal resources in this region are almost entirely bituminous. Low-sulfur coal accounts for 24 percent of the region's DRB, medium-sulfur coal for nearly 35 percent, and high-sulfur coal for more than 41 percent. Low-sulfur coal in Appalachia is concentrated in eastern Kentucky, Virginia, southern West Virginia, and in the Pennsylvania anthracite field.

The Interior Region is estimated to contain 159.6 billion short tons, or 31 percent of the DRB of U.S. coal. All of the DRB coal in the region is bituminous, except for 13.4 billion short tons of lignite deposits, primarily in Texas, and 0.1 billion short tons of anthracite in Arkansas (Table 7). More than 87 percent of the region's DRB is high-sulfur coal and only 1 percent is low-sulfur coal.

In the Western Region, the DRB is estimated at 240.0 billion short tons, which is 47 percent of the U.S. total. Subbituminous coal is most prevalent in the West, where it constitutes 77 percent of the Region's DRB, with the vast majority occurring in Montana and Wyoming (Table 7). Lignite makes up more than 12 percent of the DRB in the West, primarily in the Fort Union-age geologic deposits of Montana and North Dakota and the relatively young, Tertiary-age Gulf Coast deposits of Texas. The remainder, more than 10 percent of the Western DRB, is bituminous coal, found mostly in Colorado, Utah, and Wyoming, plus small areas of anthracite in several scattered locations. The EIA estimates that 59 percent of the DRB coal in the West is low-sulfur, that 36 percent is medium-sulfur, and that 5 percent is high-sulfur (Table 12).

Chapter 3: Page 2 | Page 3 | Page 4 | Page 5