Mount Raimer is located within Williamstown, Massachusetts and the New York towns of Petersburgh and Berlin. The Taconic Mountains continue south from Mount Raimer as Berlin Mountain and north as the White Rock ridgeline. It is flanked to the east by several hills that precede the Hoosic River Valley and the town of Williamstown. The west side of the mountain drains into the Little Hoosic River, thence into the Hoosic River, the Hudson River, and Long Island Sound. The east side drains into the Hoosic River. Petersburg Pass, located on New York Route 2/ Massachusetts Route 2, cuts over the gap between Mount Raimer and the next summit to the north, Smith Hill, at an elevation of 1,650 feet (500 m), just .75 miles (1.21 km) north of the summit of Mount Raimer.
Mount Raimer was home to lift served alpine skiing for nearly two decades. Originally known as Petersburg Pass Ski Area, the base lodge and parking lots were located adjacent to the height of land on New York State Route 2.
Due to a variety of reasons, including the steep ascent up Route 2 and the lack of water for snowmaking, the ski area struggled through much of its existence. As a result, the ski area failed to operate for multiple seasons in the 1970s. In addition, Petersburg Pass Ski Area was renamed twice in order to try to rebrand its image. After a short time as Taconic Trails, the ski area was last known as Mount Raimer. An attempt was made to dramatically expand the ski area during its final years, as trails were cut on the western face of the mountain. This expansion was never completed and the ski area went out of business in 1980. Recently, since about 2010, there has been a renewed interest in the area for backcountry skiing on a couple of the defunct trails and glades.
The double chairlift was later sold to Ski Butternut.