SEVENTIETH ANNUAL REPORT 17 



Indian Creek site (39ST15) the previous year, made a series of tests 

 at the Mathison site (39ST16), and did extensive digging at the 

 Buffalo Pasture site (39ST6). At the Indian Creek site, which lies 

 on the line of the proposed discharge channel for the Oahe Reser- 

 voir, two house floors were cleared. One, probably a ceremonial struc- 

 ture, was 50 feet in diameter. It contained a raised earthen platform 

 or altar, covered with mud plaster, along the wall opposite the entry- 

 way. Beside the altar was a bufi'alo-skull shrine. Only about 1 per- 

 cent of that site was excavated, but since it was evident that there 

 would be some delay in the construction of the discharge channel, 

 further efforts were deferred until a later field season. The Mathi- 

 son site, also on the line of the discharge channel, is stratified and the 

 tests showed it contains data on several different Indian periods. In 

 addition it probably was the location of Fort Galpin, one of the fron- 

 tier posts. Most of the activity during July, August, and early Sep- 

 tember was at the Buffalo Pasture site 1 mile upstream from the right 

 wing of the dam on the west bank of the river. A large fortified^ 

 earth-lodge village had been located there. Four earth lodges, the 

 cross section of the defensive ditch or moat, and over 210 linear feet 

 of the palisade wall inside the moat were excavated. One of the lodges 

 proved to be a ceremonial house and contained an excellent example 

 of an altar with bison-skull offerings. Although only about 8 percent 

 of the site was excavated there was an unusually large yield of arti- 

 facts. Included in the materials are over 100 restorable pottery ves- 

 sels, which is a rare find so far as the Plains area is concerned. The 

 material and information from Buffalo Pasture rounds out and helps 

 to clarify that obtained from two sites, Dodd (89ST30) and Phillips 

 Ranch (39ST14), between it and the dam which were dug during 

 previous seasons. 



While the River Basin Surveys parties were working in the Oahe 

 area in the summer of 1952 the South Dakota Archeological Commis- 

 sion and the W. H. Over Museum of the University of South Dakota 

 carried on excavations at tlie Thomas Riggs site (39HU1) under a 

 cooperative agreement with the National Park Service. On two pre- 

 vious occasions the W. H. Over Museum had worked there but had not 

 completed its investigations. During the 1952 season its party, under 

 the leadership of Dr. Wesley R. Hurt, tlr., excavated the remains of 

 five houses and dug a long trench through the village area. Evidence 

 found there indicates that the village was occupied at about A. D. 

 1500 and that it probably did not have more than 200 inhabitants at 

 any one time. Just what the relationship between it and later Ari- 

 kara or Mandan communities may have been is still to be determined. 



The two parties, one for Indian and one for historical sites, working 

 in the Fort Randall Reservoir basin continued the operations started 

 toward the end of the preceding year. During the field season excava- 



