to cross a river―(泳いでなら)―swim across a river―(徒歩でなら)―wade (across) a river―ford a river―(馬でなら)―ride across a river
to cross a river―(泳いでなら)―swim across a river―swim over a river―(徒渉してなら)―wade across a river―ford a river―(渡し舟でなら)―ferry a river―cross a ferry
川岸で