Translation of "고원에" in English

꽤 힘들고 느린 방법이었지만 선구자들도 이 방법으로 고원에 갔었기 때문에

It was hard, slow work, but the route they were on had reached the plateau before, and

영국팀은 남극이 있는 극지 고원에 가기 위해 인간의 힘으로 빙하를 오르고

And they believed man-hauling was the surest way to make the tricky climb up the glacier