The walkers' passes of Nan Bield and Gatescarth provided historic trade routes from Mardale to Kentmere and Longsleddale respectively. With the submergence of Mardale Green village beneath Haweswater reservoir in the 1940s, their original purpose has died, but both routes still provide good access for fellwalkers and are the easiest ways onto Harter Fell. The upper sections still bear the original zig-zags over steep ground. The fell is most frequently climbed from Mardale, as there is road access along the shore of Haweswater. Harter Fell summit is 1 mile or 1.5 km southwest and 1,800 ft or 550 m above the carpark at the head of the reservoir. Crags block a direct ascent, however, and Harter Fell is thus normally climbed via Gatescarth Pass to the east of the summit, or Nan Bield Pass to the west. These two passes also provide the easiest access from Kentmere or Longsleddale.