The road has been built on a terrace which was once the flat bottom of glacial Lake Springfield (37.8), but at the north end of the city it descends towards the Connecticut River, utilizing the contact between the red layers of Longmeadow sandstone and the massive, dark green Granby tuff with large volcanic bombs that are visible from the road. The twin entrances to Mountain Park (38 and 38.2) may tempt the motorist to indulge in an attractive side trip, but there is enough to occupy him on the main highway. Nearer the river (38.5), a ledge slopes from the roadway to the railroad tracks and to a series of riffles in the stream. This is the Smith’s Ferry footprint locality (pp. [66]-67), and the widened highway and the entrance to the ledges offer an invitation which cannot be declined (38.6).
North of the dinosaur tracks, road, railroad and river run parallel. Lateral roads are few, but there is a gateway (40.2) into the Mount Tom Reservation. The Granby tuff, which has outcropped persistently on the west side of the road, rises to a high bluff and then passes eastward beneath the river (40.6). The underlying second lava replaces it in the road cuts and is especially conspicuous along the railroad (40.9). The next dark gray bluff west of the road (41.4 to 41.6) is part of the Holyoke flow which caps the Mount Tom and Mount Holyoke ranges (see pp. [26]-27). Soon it, too, crosses the river to Titan’s Pier (pp. [60]-61), and old residents say that a ledge of it outcropped in the river bed at low water before the Holyoke dam raised the water level. Directly ahead, southward-dipping beds of conglomerate outcrop on either side of the road (41.0); these beds underlie the lava forming the gentle southern slopes of the ranges, and their position beneath the trap can be seen plainly on the steep northern slopes.
The road through the Mount Tom Reservation rejoins the highway (42.2) just south of the outlet from the Oxbow Lake (42.3), the upper end of which also loops ’round and abuts against the highway (42.7). (See [p. 3].) Annual floods inundate most of this section, and even the banked-up road and railroad periodically go under the swirling waters of the swollen river. A sign (43.5) announces that the roadway was 13.5 feet below water at the height of the 1936 flood, but it is hoped that the new dike at the southern limit of Northampton will hereafter turn the floods away from the lower sections of the city. Federal Highway 5 bears right (44.0), and the road ahead continues into the Berkshire Trail. Of passing interest is the fact that a well drilled near this junction penetrated 3,700 feet of Triassic arkose without reaching the crystalline rock floor. The road crosses the unused bed of Mill River (44.2) and comes once again to the Court House corner in Northampton (44.6).
Belchertown, Amherst, and Northampton
In our first tour we noted that a road (Route 9) turns right to Amherst at the south end of the Daniel Shays Highway (21.1), and if we will return to this junction, it will be worth our while to make the Amherst run. Just beyond the intersection the highway traverses the level gravel plain of a nice margin lake (see [p. 7]) before it descends (22.0) toward the Lake Hadley plain. Erratic boulders and stone fences are abundant on the slope, and the bedrock is part of the pre-Triassic complex. One very interesting pegmatite contains inclusions of contorted schist (23.2). The road soon leaves the rocky slopes for the gravel plain of Lake Hadley, but only a short distance northward and westward lie the Belchertown Ponds, which seem to occupy a large and deep kettle hole area (see pp. [7]-8).
The road winds through pine-clad kame terraces, left on the margin of the ice which filled the Lake Hadley basin; and where it emerges from the woods (24.4), the line of hills making the Holyoke Range may be seen stretching westward in a series of sharp points. These are the projecting edges of the Holyoke lava flow which resisted erosion after all the softer sediment and volcanic debris flanking it were removed.
The road to Mount Lincoln turns right at Pansy Park (24.9), and north of this point the Amherst road follows a kame terrace between the Pelham Hills on the right, and the former ice-filled bed of glacial Lake Hadley on the left. Ultimately (27.1) the highway leaves the terrace and drops to a delta which was deposited in Lake Hadley. The view northward shows Mount Toby and Mount Sugarloaf outlined sharply, and to the east near the Orient, the sharp V-shaped notch of the north fork of Fort River cuts one of the kame terraces. The delta deposit (27.5 to 27.7) shows excellent fore-set beds in the gravel pit (27.7), and its entire surface is dotted with ponds which occupy irregular kettle holes (see pp. [7]-8).
The highway continues down the delta slope and crosses the Fort River (28.4). This river established a meandering course upon the bed of Lake Hadley, but its floodplain is now excavated below the level of the lake deposits, which form a terrace above the stream. The road passes through Amherst (30.2) and returns to Northampton (37.4) by the outbound route.
South Hadley, Amherst, Northampton
The route 116 north from the road junction at South Hadley Falls (33.2) also has its points of interest. After it passes over the deeply dissected deposits in Lake Springfield, it rises above the old lake level at the Mount Holyoke campus (35.1) and continues at this higher elevation beyond the Hockanum-Amherst fork (35.9) in the center of South Hadley. Along the right fork (State Highway 116), which leads to Amherst, horizontal Longmeadow sandstone outcrops west of the road (37.1) where the slope to the valley of Bachelor Brook begins. The flat lake plain extends from Moody’s Corner (37.4) to the base of the Holyoke Range. A gravel road turns right from the highway (38.2) and crosses the brook one mile east, and from this locality were excavated many of the excellent dinosaur footprints in the Amherst College collection.