The Hellroaring mining district, known exclusively for its chromite deposits, is located southwest of Red Lodge near the Montana - Wyoming border. The district includes the upper reaches of Rock Creek and the Line Creek and Hellroaring Plateaus in the Beartooth Mountain range. A pair of prospectors, working for J. F. Brophy of Red Lodge, located the first chromite in the region in 1916. Their Four Chromes claim in the neighboring Silver Run District sparked the interest of M. E. Martin, another local prospector. He took up the search, locating all the other known chromite deposits in the area before he died in 1937 (James 1944).
The rugged region consists of high plateaus, ranging from 10,000 to 11,000 feet in elevation. Rock Creek, Line Creek, and their tributaries flow through deeply incised glaciated valleys characterized by steep walls and rounded bottoms. The underlying rock is primarily granite and gneiss, while the sequence of metamorphic rocks includes hornblendite, hornblende schist, quartzite, and serpentine, the host rock for chromite. Younger rocks, represented by diocite, granodiorite porphyry, syenite porphyry, and pegmatite dikes, cut through the underlying rocks. The entire region is crossed by numerous faults. The chromite deposits are located on Hellroaring Plateau, with minor deposits located on Line Creek Plateau, all above 8000 feet in elevation (Schafer 1937; James 1944).
Prospector Martin was one of the parties forming Montana Chrome, Inc. in 1933 to develop the chromite deposits of the Hellroaring Plateau. By June of that year, the company was shipping concentrates to Great Falls for refining at the Anaconda Copper Mining Company's reduction works. Although Montana Chrome announced plans to build a 30-ton concentrator at the mouth of Hellroaring Creek, apparently the company did not follow through with the proposal. Mining continued the next year, with workers removing 2000 tons of ore and locating more than 10 times that amount in the ground. The company announced that the ore ran 70 percent chrome and 30 percent iron (James 1944; Mining Journal 1933, July 1934, and September 1934).
Following a lull during the late 1930s, U. S. Vanadium Corporation leased Montana Chrome's claims in 1941, working them until at least September 1943. The corporation contracted with Stearns-Rogers Corporation for construction of a chrome gravity concentration plant to process ore from the mines. Located on the site of the vacated East Bench coal mine near Red Lodge, the mill was completed in 1942 and had a capacity of 450 tons per day. During its short run from March to November 1942, the mill turned out 11,689 tons of concentrate. The resumption of foreign imports and changes in government regulations, however, forced U.S. Vanadium to close the mill late in 1942. The buildings burned nine years later (Anderson 1983; James 1944).
Production totals from October 1941 through September 1943 included 67,943 tons of ore, 11,689 tons of concentrates, and 21,958 tons of crude lump ore. The concentrates averaged nearly 40 percent Cr2O3, while the crude lump ore contained 32 percent. The important claims in the district include the Drill, Gallon Jug, Highline, North Star, and Pick (James 1944).
BOUNDARIES OF THE DISTRICT
Although there are no written descriptions of the boundaries of the Hellroaring district, the district is defined by the location of the claims. James (1944) describes deposits located in two separate areas: the Hellroaring Plateau between Rock Creek and Lake Fork of Rock Creek, and Line Creek Plateau between Wyoming Creek and the main fork of Rock Creek. Figure 1 shows the separate areas described by James (1944) within the large area as defined by the AMRB (1994).
HISTORIES OF SELECTED MINES
One of the many chromite claims located by M. E. Martin, the Drill claim had a large area of chromite float along with a deposit that continues into the North Star claim. Samples of the massive ore showed 32.26 percent Cr
, 20.55 percent iron, and 3 to 4 percent uvarovite, a green chrome garnet. U. S. Vanadium Corporation removed 1691 tons of ore in 1942 (James 1944; Schafer 1937).
Gallon Jug Claims
Gallon Jug No. 4 held the most promise of these four claims found by M. E. Martin. Located on the south rim of Hellroaring Plateau, at the head of Lost Picket Basin, the ore body was contained in a complex landslip. In addition to the lenses of ore, there was a large quantity of chromite float, indicating that the strike length might be as much as 200 feet. Three identified deposits contained massive ore, most in a fine grained talc matrix. U. S. Vanadium Corporation removed 529 tons of ore in 1943, and the next year James (1944) estimated that up to 10,000 tons remained. The same company took 1,283 tons of ore from the Gallon Jug No. 2 claim but had to stop work in the fall of 1942 because of problems caused by diabase (James 1944; Schafer 1937).
The Highline claims are located on the northern tip of the Line Creek Plateau, between Wyoming Creek and the main fork of Rock Creek. U. S. Vanadium Corporation mined the deposits with open pits from October 1941 to June 1942, removing 23,964 tons of ore. Quite a bit of the initial ore was in the form of chromite "sand" from weathered outcrops. Waste rock became a problem as the pits deepened, and the company stopped work. In 1943, however, N. W. Staley and Tony Rom leased the claims, put in an incline and removed 126 tons of ore which they sold to U. S. Vanadium Corporation (James 1944).
North Star Claim
The North Star Claim contains the largest body of chromite in the Hellroaring district. It is located on the eastern edge of the Hellroaring Plateau, overlooking a basin known as the "Pocket." Operators, probably U. S. Vanadium Corporation, removed 35,000 tons of ore from an open pit and shipped nearly half of this as crude lump. While this ore averaged 25 percent Cr
, a few carloads of lump ore ran as high as 41 percent. The primary matrix for the ore was antigorite serpentine (James 1944).
Located on the eastern side of the Hellroaring Plateau, the Pick mine contained large blocks of massive ore separated by talcose serpentine. M. E. Martin performed the initial work on the claim, driving two short adits. Montana Chrome, Inc. had taken out 30 tons of massive ore by the late 1930s, with samples showing 34.94 percent Cr
and 20.58 percent iron. The company planned to work mostly from the lower Pick adit, shipping the ore out with an aerial tramway down to a proposed plant on Rock Creek. Later operators used a large open cut to extract the ore, with more removed by stoping from a lower crosscut. U. S. Vanadium mined 5,343 tons of ore in 1942 (James 1944; Schafer 1937).
Less important chromite claims in the district include the Bluebird No. 2, Pocket, Rainbow No. 4, and Shovel (James 1944; Schafer 1937).
Abandoned Mine Reclamation Bureau (AMRB)
1994 Mining districts of Montana. Maps 1:100,000 and Map #94-NRIS-129. Compiled and edited by Joel Chavez. Prepared by Montana State Library Natural Resource Information System (NRIS) for Montana Department of State Lands. Helena
1983 Cultural Resource Inventory and Evaluation: Red Lodge East Bench - Washoe - Highway - Burns - Smith Mines. Prepared for Montana Department of State Lands by Cultural Resource Division, GCM Services, Inc., Butte.
James, H. L.
1944 Chromite Deposits near Red Lodge, Carbon County, Montana.
U.S.G.S. Bulletin 945-F
1933 30 June:15-16.
1934 30 July:20.
1934 30 September:19.
Ferguson, Henry Gardiner and L. P. Benedict
Montana Bureau of Agriculture, Labor and Industry, 11th Biennial Report
Schafer, Paul Abbott
1937 "Chromite Deposits of Montana",
Montana Bureau of Mines and Geology
, Mem. 18, Montana School of Mines, Butte.
Work Projects Administration (WPA), Mineral Resources Survey.
Montana Mine Index, and Alphabetical Index Arranged by Counties, Districts and Mines of Information on Montana Mines from 1867-1940
. Montana School of Mines, Butte.