▁Si oux ▁ra iders ▁in ▁the ▁spring ▁of ▁ 1 8 6 4 . ▁ ▁An ▁important ▁imp et us ▁to ▁another ▁military ▁campaign ▁against ▁the ▁Si oux ▁was ▁the ▁desire ▁to ▁protect ▁lines ▁of ▁communication ▁with ▁recently ▁discovered ▁gold fields ▁in ▁Mont ana ▁and ▁Id aho . ▁ ▁The ▁lif eline ▁for ▁the ▁American ▁gold ▁min ers ▁were ▁steam bo ats ▁p lying ▁the ▁Missouri ▁River ▁through ▁the ▁heart ▁of ▁Si oux ▁territory . ▁During ▁the ▁winter ▁of ▁ 1 8 6 3 - 1 8 6 4 , ▁Sul ly ' s ▁superior , ▁Major ▁General ▁John ▁Pope ▁ordered ▁Sul ly ▁to ▁establish ▁several ▁for ts ▁along ▁the ▁Missouri ▁River ▁and ▁in ▁the ▁eastern ▁Dak ot as ▁to ▁secure ▁the ▁communication ▁routes ▁to ▁the ▁gold fields ▁and ▁to ▁eliminate ▁the ▁Si oux ▁threat ▁to ▁the ▁sett lers ▁east ▁of ▁the ▁Missouri ▁River . ▁ ▁Sul ly ' s ▁First ▁Brigade , ▁consisting ▁of ▁up ▁to ▁ 1 , 7 0 0 ▁men , ▁followed ▁the ▁Missouri ▁River ▁from ▁its ▁starting ▁point ▁at ▁Si oux ▁City , ▁Iowa . ▁ ▁The ▁Second ▁Brigade ▁with ▁about ▁ 1 , 5 5 0 ▁men ▁would ▁march ▁over land ▁from ▁Fort ▁R id g ely ▁in ▁Minnesota . ▁On ▁the ▁march ▁up ▁the ▁Missouri , ▁the ▁Si oux ▁killed ▁one ▁soldier ▁and ▁wounded ▁another . ▁ ▁The ▁three ▁Si oux ▁perpet rat ors ▁were ▁caught , ▁killed , ▁and ▁dec ap itated . ▁▁ ▁Add itional ▁soldiers ▁and ▁civ ili ans ▁with ▁ 1 5