▁three ▁well - equ ipped , ▁state - of - the - art ▁steam bo ats . ▁Major ▁Long ▁later ▁followed ▁with ▁the ▁scientific ▁party ▁of ▁" Ar my ▁Engine ers " ▁ab o ard ▁the ▁Western ▁Engine er , ▁leaving ▁in ▁June . ▁Notable ▁expedition ▁members ▁included ▁Captain ▁Stephen ▁K ear ny ▁( l ater ▁military ▁governor ▁of ▁California ), ▁landscape ▁painter ▁Samuel ▁Se ym our , ▁natural ist ▁and ▁painter ▁Tit ian ▁Pe ale , ▁and ▁zo ologist ▁Thomas ▁Say . ▁ ▁At kin son ' s ▁party ▁suffered ▁a ▁variety ▁of ▁problems ▁from ▁the ▁out set , ▁including ▁an ▁in efficient ▁and ▁cor rupt ▁steam bo at ▁captain . ▁Five ▁steam bo ats ▁had ▁been ▁contract ed ▁for ▁At kin son , ▁but ▁two ▁had ▁not ▁reached ▁the ▁Mississippi ▁at ▁all ▁and , ▁of ▁the ▁remainder , ▁a ▁third ▁( the ▁Thomas ▁Jefferson ) ▁was ▁soon ▁found ▁in cap able ▁of ▁navig ating ▁the ▁numerous ▁sn ags , ▁sand bars ▁and ▁curr ents . ▁She ▁and ▁her ▁crew ▁were ▁left ▁behind , ▁some ▁forty ▁miles ▁below ▁Franklin . ▁The ▁last ▁two ▁( the ▁R . M . ▁Johnson ▁and ▁the ▁Ex ped ition ) ▁also ▁could ▁not ▁advance ▁through ▁the ▁tre acher ous ▁obst acles ▁and ▁were ▁stopped ▁just ▁above ▁the ▁mouth ▁of ▁the ▁Kansas ▁River , ▁to ▁winter ▁at ▁Cow ▁Island ▁and ▁return ▁to ▁St . ▁Louis ▁in ▁the ▁spring . ▁After ▁several ▁days ▁and ▁many ▁miles , ▁At kin son ' s ▁troops ▁had ▁to ▁resort ▁back ▁to