[Journal entry for February 7, 2010] Dallas and I hike to the Irish Potato, a large glacial boulder just off the Suffern - Bear Mountain (SBM) Trail, atop of Irish Mountain. We park on Route 106, on a lot near where the SBM crosses the road. The trail first follows Minisceongo Brook, the outflow of Lake Welch. The walk down to the brook, which is flowing strongly, and examine ice formations along its edhes. The bedrock in the area is a gneiss. We come across a big erratic boulder of Skunnemunk Conglomerate, full of fist-sized clasts. The trail then heads uphill, towards the summit of Irish Mountain. We cross several little streams, one with a beautiful ice cascade. We pick our way carefully, detouring off the trail, which is icy and trecherous. The Irish Potato is at the top of the hill. It dwarfs Dallas when she stands next to it. The boulder is of the same granite that composes many of the hilltops in the Park, so I would not describe it as erratic, though its round shape suggest that it has been transported a significant distance and not just plucked out of the hillside. The park is full of plucked hillsides and giant blocks, like the giant blocks that make up the Lemon Squeezer, but as a rule they are much more angular than is this one. We return via reversing out route on the SBM. We notice a large pile of boulders along side a flat part of the trail. I suppose it was created long ago by a farmer clearing stones to make a pasture in this spot. I walk down to the Minisceongo Brook again, just before arriving at Route 106.