Seneca Bluffs is one of the newer trails to the area and connects the Chesapeake and Ohio Canal Towpath to Seneca Ridge Trail at the intersection with Black Rock Road at Black Rock Mill. The trail mainly packed clay and dirt with a couple of bridges. The highlight of this trail is the approximately 50-foot stream crossing! Don't worry, it's easier than it looks. There are some moderate climbs on this trail but nothing too steep or too lengthy. Most of the descents can be ridden quite fast and are a ton of fun.
All but the last 100yards of this trail are in Seneca Creek State Park. The last section, just before River Rd., is on Montgomery County Park Land.