Leitrim Lodge car park, AKA the BB Hut, is due west of col between Rocky Mountain and Tornamrock on the Sandbank Road. Grid Reference - J 224 256
Travel through Banbridge, Rathfriland and Hilltown, turning left at the former church in the middle of Hilltown (pictured below) towards Castlewellan and Newcastle.
After approximately 743 metres, turn right towards Newcastle on the B27 and continue on this road following the signs for Kilkeel and Spelga Dam. In about one mile the road branches left towards Newcastle but ignore this and continue straight on the B27 towards Splega and Kilkeel for a further 500 metres to the crossroads, turning right on the Sandbank Road, signed to Rostrevor and (possibly) Santa's Cottage.
Leitrim Lodge car park is on your left a little over two miles down the Sandbank Road, just past the BB Hut. Leitrim Lodge car park is not to be confused with the Hen Track car park which you will pass, on your right, as you drive towards Leitrim Lodge.
Yellow Water picnic area is a little over 2 miles beyond Leitim Lodge travelling south towards Rostrevor - Sandbank Road becomes Newtown Road. You will see the parking/picnic area through the trees on your left.
Alternative route: drive "straight" through the square in Hilltown i.e. round the church towards Rostrevor and 400 metres beyond the square (after the big hall on your left) take the road to your left, Leitrim Road, and follow this down to T junction at the end of the road. Turn right and the Leitrim Lodge car park is almost immediately on your left, just past the BB hut. It's a shorter and some say easier route but on a narrow winding road so you may be delayed by large vehicles.
There are public toilets to the left of the church in Hilltown (when viewed, as above, from the north / Rathfriland side).