The Petroleum Lake trail follows Anderson Creek gradually climbing an old jeep road and passing through fir forests before emerging into alpine tundra. Privately owned log cabins are visible. The alpine tundra is extremely fragile--please stay on established trails. In about 1 mile the trail forks. The left fork reaches Anderson Lake in another 1/4 mile. To access Petroleum Lake retrace your steps and take the right fork. Petroleum is 3/4 of a mile farther. The trail continues its ascent through alpine meadows and tundra before coming to an outlet stream for Petroleum Lake. Cross the stream. The trail then begins a very steep ascent for 200 yards before leveling out. Petroleum Lake is just ahead beyond the rise on the left. To the right of the lake the trail ascends for a short distance up to a high alpine pond. It then skirts to the right of the pond and rises gently to a saddle which provides exploration of the rocky knolls and breathtaking views of the Collegiate Wilderness. This short extension is well worth the effort.