▁steam bo ats ▁ch ug ged ▁up ▁the ▁Missouri ▁River ▁to ▁support ▁the ▁army ▁on ▁the ▁ground . ▁ ▁Sul ly ' s ▁two ▁columns ▁of ▁soldiers ▁un ited ▁on ▁June ▁ 2 9 ▁and ▁on ▁July ▁ 7 ▁he ▁established ▁Fort ▁R ice ▁on ▁the ▁Missouri ▁River ▁in ▁North ▁Dak ota ▁as ▁a ▁base , ▁supplied ▁by ▁steam bo at , ▁for ▁his ▁military ▁expedition . ▁▁ ▁His ▁sc outs , ▁Win ne b ago ▁and ▁friendly ▁Si oux ▁and ▁mixed - blo ods , ▁informed ▁him ▁of ▁a ▁large ▁enc amp ment ▁of ▁Si oux ▁ 1 3 0 ▁miles ▁north west ▁near ▁the ▁Little ▁Missouri ▁River . ▁ ▁On ▁July ▁ 1 9 , ▁he ▁and ▁his ▁men ▁depart ed ▁Fort ▁R ice ▁to ▁search ▁for ▁the ▁Si oux ▁enc amp ment . ▁ ▁Sul ly ▁was ▁enc umber ed ▁by ▁a ▁w agon ▁train ▁of ▁ 2 0 0 ▁min ers ▁and ▁their ▁families ▁head ed ▁for ▁the ▁gold fields ▁who ▁he ▁rel uct antly ▁agreed ▁to ▁protect ▁and ▁esc ort . ▁ ▁Sul ly ' s ▁sc outs ▁reported ▁ 1 , 5 0 0 ▁to ▁ 1 , 8 0 0 ▁tip is ▁in ▁the ▁Si oux ▁enc amp ment . ▁ ▁Sul ly ▁believed ▁he ▁would ▁be ▁faced ▁by ▁ 5 , 0 0 0 ▁to ▁ 6 , 0 0 0 ▁war riors . ▁ ▁The ▁Si oux ▁later ▁claimed ▁they ▁had ▁ 1 , 6 0 0 ▁war riors ▁in ▁the ▁battle ▁– ▁likely