The Maury River has been cutting its channel downward over many millions of years; that process, along with blasting for the railroad and canals, exposed large sections of cliff face along the trail. Users should beware of falling rocks along these sections and refrain from standing too close to the rocks.
Along the trail, users can see evidence of the Alleghenian Orogeny – the most recent period of mountain-building in the area. Many of the sedimentary rock layers seen along the trail were formed when this area was an ancient sea before the mountains were formed. As the Maury River has deepened its path, it (like most rivers) has undercut banks on the outside of curves and meanders. This can cause small landslides as banks collapse into the stream, and trail users might see spots of erosion at the edges of the trail as a result.
The Chessie Trail is located in the Valley and Ridge physiographic province, which contains younger rocks formed in the Cambrian Period, early in the Paleozoic Era. These rocks are much younger than those found in the Blue Ridge. The sedimentary rocks seen along the trail were folded and faulted during the mountain-building that formed the Appalachians. Rock formations seen along the trail include (starting with the Lexington end) the Edinburg Formation, Conococheague Formation, and Elbrook Formation. The deformation of these sedimentary rocks becomes apparent when examining the layering visible along the trail. Deformation can be observed on a large scale (massive rock outcrops) or a small scale (folds in the small-scale layers of sediment). Toward the Buena Vista end of the trail, users will see many caves higher up in the rock face; these were formed from the dissolution of limestone bedrock long after the area’s mountain-building event.
Two U.S. Geological Service gauging stations are present along the Maury, with one visible along the trail downstream of the confluence with South River. The highest flooding on record in the area was in August of 1969 when Hurricane Camille struck the area. The height of the water at that point would have covered the Chessie Trail with 10-15 feet of water. This flood halted the railroad usage in the area, and various other floods have washed out pedestrian bridges (at South River and Jordan’s Point) and done further damage to the trail.
The Maury River has relatively high-quality water, but is degraded along the trail as polluted tributaries flow into the river. Along the trail, the watershed shifts from forest-dominated to agriculture-dominated. Agricultural operations tend to contribute large amounts of nitrogen, phosphorus, fecal coliform, and sediment – some of the most serious pollutants in aquatic ecosystems – through runoff. Parking lots, interstates, buildings, and other city infrastructure also contribute high levels of pollution.
Rockbridge County is part of the Chesapeake Bay watershed, and water seen along the trail will eventually end up there. Just as polluted tributaries lower the water quality of the Maury, the Chesapeake Bay suffers from severe pollution that it receives from all of its upstream tributaries – spanning four states. Land-use practices and poor pollution management in watersheds can compound pollution downstream, whether it is in the Maury River or the Chesapeake Bay. These issues can only be mediated through a watershed-based approach that considers all connecting waterways.
The city of Lexington gets its water from the Maury River not far upstream of the start of the trail. The Maury Service Authority outflow pipe (carrying water after being treated by the Wastewater Treatment Plant) flows back into the river along the trail – a typical way to dispose of treated water. Wastewater treatment plant effluent can pollute waterways because of high levels of nitrogen, chlorine, sodium, fluoride, and other chemicals. Although aquatic ecosystems require and use nitrogen, any excess is passed downstream and becomes a problematic pollutant. An upgrade project, completed in December 2011, was necessary for the treatment plant to comply with new nutrient limits. The project will help reduce the local area’s pollution contribution to the James River and the Chesapeake Bay.