The Traprock Landscapes of New England. Peter M. LeTourneau

been providing high-quality fruit and produce since 1741, is a major tourist attraction featuring a farm market, pick-your-own fruits and pumpkins, seasonal activities, and three golf courses.

      Established on the northern flank of Sleeping Giant ridge in 1904, Blue Hills Orchard overlooks Meriden’s Hanging Hills—from left (west) to right (east), West Peak, East Peak, Merimere Notch, and South Mountain. The prominent “step” beneath West Peak (left) is the Talcott Basalt, the oldest (lowest) lava flow in the Connecticut Valley.

      Taking advantage of the long steady slopes and snowy New England winters, Mount Tom Ski Area in Holyoke, Massachusetts, and Powder Hill Ski Area (now Powder Ridge) at Beseck Mountain in Middlefield, Connecticut, were developed during the alpine-skiing boom of the mid-twentieth century.

      Postcards from 1960s: Mount Tom Ski Area; the “Big Tom” trail; NASTAR race day at Mount Tom; Powder Hill Ski Area. Images: author’s collection.

      By the late 1800s, however, the growth of the major cities and towns brought a newfound appreciation of the traprock hills as valuable watersheds, and numerous water-supply reservoirs were constructed along the length of the Connecticut Valley. Even in the modern era, the formidable slopes, shallow depth to bedrock, and the difficulties of providing water and on-site sewage treatment precluded most residential and commercial developments on the traprock hills. As a result, the volcanic ridges remained largely undeveloped, becoming the most important natural corridor in southern New England, a vital green belt called “Connecticut’s Central Park” by Wesleyan professor Jelle de Boer.

      Meteorologists associate the Connecticut Valley with a distinct climate corridor in southern New England typified by warm humid summers and mild winters in comparison to the cooler surrounding hills. The floor of the Connecticut Valley rises from sea level at New Haven to an average of about 150 feet above sea level near Northampton; many glacial hills and terraces form elevations over 250 feet throughout the valley. As a result of its generally moderate elevations the Connecticut Valley enjoys a long growing season, averaging about 165 days in Hartford, but ranging from a high of 207 days in New Haven to a low of 125 days in Amherst. Precipitation is evenly distributed throughout the year, but occasional droughty periods typically occur in late summer. The central and northern Connecticut Valley average about 45 inches of precipitation annually; the southern coastal region near New Haven is slightly wetter with about 47 inches of precipitation. Summers in the Connecticut Valley are warm and humid, with an average high temperature in July of about 82°F. The generally mild winters have average high temperatures ranging between 30°F and 40°F, characterized by rain and freezing rain near New Haven, and snow north of Hartford.

      The cold average winter temperatures and the long steady slopes of the traprock ridges fostered the development of two major ski areas in the Connecticut Valley. Powder Ridge Ski Area on Beseck Mountain in Middlefield, Connecticut, has been in operation nearly continuously since the 1950s. Mount Tom Ski Area operated on the traprock ridge of the same name near Holyoke from 1962 to 1998. Both Powder Ridge and Mount Tom ski areas were pioneers in the technology of snowmaking, necessary to supplement the unreliable natural snow.

      For physical geographers and artists the signature landscape elements of the Connecticut Valley are the “tilted” traprock ridges, or cuestas, with steep cliffs on their upturned edges and extensive upper surfaces sloping about 15 degrees. The ridges generally have west-facing cliffs and east-dipping slopes, but their particular configuration depends on the local trend of geologic structures. In the southern Connecticut Valley, the crescent-shaped trends of Totoket Mountain and Saltonstall Ridge result from regional-scale folds in the rock layers. A broad fold also creates the unusual east-west orientation of the Holyoke Range in the northern Connecticut Valley. Numerous faults that offset the traprock layers in the central Connecticut Valley created the spectacular “crag and notch” topography in the picturesque region from Mount Higby to Ragged Mountain.

      Now part of the Meriden Land Trust, the green pastures of the former Bilger Dairy nestle beneath the cliffs of Chauncey Peak, Meriden, Connecticut. Dozens of family-owned dairy farms once flourished on the rolling glacial hills in the central Connecticut Valley. Today, only a few working dairy farms remain.

      Snow softens the traprock landscapes at the former Bilger Dairy farm in Meriden. The early twentieth-century farm buildings seen here were built on ledges and outcrops of lava.

      Hayfields in the central Connecticut Valley. With warm, moist summers and mild but often snowy winters, the Connecticut Valley enjoys the longest frost-free growing period in southern New England, exclusive of the coastal zone. Owing to the favorable climate, the Connecticut Valley produced some of the highest and most profitable yields of hay and corn in the nation in the early to mid-nineteenth century. Westfield Road, Meriden.

      The Hanging Hills, including, from right rear to middle foreground, East Peak, Merimere Notch, South Mountain, Cathole Notch, and Cathole Peak, are the most rugged and picturesque traprock landforms in the Connecticut Valley. Termed cuestas by physical geographers, the characteristic “tilted” landforms were created by eons of earth movement and erosion. View from Chaucey Peak.

      Rising abruptly in amphitheater-like ranks of rugged talus slopes and sheer cliffs, the traprock hills of the Connecticut Valley have a greater topographic prominence than many of the taller but more rounded mountains in New England. Thus, these “mountainous hills” project a more dramatic alpine aspect than anticipated from their relatively moderate elevations. For example, the southern cliffs of East Rock and West Rock near New Haven reach elevations of only about 350 feet and 400 feet, respectively, but because they rise in sheer cliffs from the tidal creeks at their base, they tower over the city, and once served as important landmarks for ships navigating Long Island Sound. A great east-west-oriented inlier of the Western Range, the Sleeping Giant massif (el. 708 ft.) in Hamden commands the Quinnipiac River lowlands as the largest isolated traprock landform in the Connecticut Valley. Noteworthy as the highest summits near the Atlantic coast south of Maine, West Peak (el. 1,024 ft.) and East Peak (el. 978 ft.) of Meriden’s Hanging Hills similarly dominate the topography of the central Connecticut Valley. Mount Tom (el. 1,202 ft.), the tallest traprock summit in the Connecticut Valley, towers more than 1,000 feet above the Manhan River valley near Easthampton, Massachusetts. Nearby, the western cliffs and ledges of Mount Holyoke drop more than 800 feet to the extensive agricultural fields on the Connecticut River floodplain.

      Because of the sheer number of traprock peaks, crags, cliffs, and ridges making up the volcanic landforms of the Connecticut Valley, and a long history of human occupation, a large number of formal and informal names have been attached to the hills. Many of the designations have changed since colonial times, and the geographic names also vary with the local frame of reference; thus, East Mountain may well be West Mountain, depending on one’s point of view. The nomenclature of the traprock hills is based on the following: geography (East Rock, West Rock, West Peak, East Mountain, South Mountain); topography and appearance (Ragged Mountain, Peak Mountain, Pinnacle Rock, Short Mountain, High Rock, Tri-Mountain, Bluff Head, Sugarloaf, the Hedgehog); nearby towns (Farmington Mountain, Meriden Mountain, Avon Mountain, West Suffield Mountain); wildlife (Rattlesnake Mountain, Rabbit Rock, Cathole Peak, Goat Peak); historic associations (Mount Tom, Mount Holyoke, Chauncey Peak, Mount Higby, Peter’s Rock, Hachett’s Hill); the first inhabitants (Totoket, Pistapaug,