Take the road leading downhill and south past Sentinel Trail parking to a sign pointing to Twin Sisters (north) and Indian Head (south). Park in the lot next to the outhouses. Twin Sisters and Brother Buttress are a short walk uphill and north from there. Or, you can walk from the base of Sentinel (access from bridge to the south of South Park entrance or from Sentinel Trail) and follow Rt. 84 to a dirt access road blocked by gate, near Twin Sisters parking. The trail direct from Sentinel is marked "closed" as of May 2018.