The second-tallest of the Black Buttes — eroded remnants of an extinct stratovolcano predating Mount Baker — climbed as a side trip from the standard Coleman-Deming approach on Baker's north side.
Approach as for Mount Baker's Coleman-Deming route and Colfax Peak: drive to the Heliotrope Ridge Trailhead, hike the climbers' trail to the edge of the Coleman Glacier, and establish a base camp around 6,000-7,000 feet along the ridge near the Buttes. Rope up and travel the Coleman Glacier toward the saddle between Mount Baker and Colfax Peak, staying well clear of the Black Buttes' base to avoid avalanche and rockfall exposure from the steep rock walls above. From around this saddle area, leave the main Baker route and follow easy slopes — a lava ridge or snow slopes, depending on conditions — for roughly an hour to Lincoln Peak's summit.
Reverse the easy slopes back to the saddle area and down the Coleman Glacier to camp.