The Granby-Holyoke road (Federal Highway 202) turns right at the south end of the Belchertown common (22.0). After crossing the railroad (22.4), it passes out upon the plain of glacial Lake Springfield (25.3) where the stone fences cease to line the roads, because the lake deposits cover the glacial boulders. Rocky islands in glacial Lake Springfield surmount the flat lacustrine plain (26.9). Granby is situated on a long rolling point (28 to 31.6) that is underlain principally by flat-lying arkosic conglomerate, but more ancient crystalline rocks appear just a little farther east. In this section the lake plain is very narrow, and the drop to the Connecticut River Valley begins at 32.3 miles and continues to the junction with the South Hadley road (33.2), where varved clay (see pp. 4-7) makes its appearance in the pits to the right of the highway. The itinerary of this excursion continues on Federal Highway 202 through Holyoke in preference to the alternate routes through South Hadley and thence either by way of Hockanum (p. 85) or via Amherst (pp. 83-84) to Northampton. The Holyoke road crosses the Connecticut River (33.8 to 34.1) where the Longmeadow or youngest Triassic sandstone appears in a series of serrate ledges between the bridge and the dam at the right. Mud-cracks on some layers and ripple marks on others tell of wet and dry seasons at the time they were formed. The route turns right just south of the Holyoke post office (34.6) and right again into Federal Highway 5 (36.2), which parallels the river. 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).