(Directions: Go south on Watson Road from Stone road. Park on east side of road where the shoulder is slightly wider.)
The parking area is just north of the Eramosa River: there is a little fence and a gate that leads into the trail (also known as a stile).
The trail is very well defined, about 8 feet wide and starts out well covered by trees. There is a side trail not far from the start that goes off to the left: you will be returning by this trail. It is easy going all the way, about 2 kilometers at which point the trail veers to the right in a clearing and you can see an expanse of water created by a dam. This branch of the trail used to continue to the right over the dam and towards Erin but the City of Guelph has now blocked foot traffic over the dam apparently due to fear of litigation resulting from accidents. The only way to get to the other side of the river and follow the trail is to start at another location south of the Eramosa River on Watson Road. (Reference required.) You can still walk over to the water, but you can't get on the dam.
Giving up on crossing the dam you can continue on the main trail in the same direction you started straight ahead for about 10 more minutes where you will encounter a fence across the trail and no trespassing signs thanks to the new landowner (around 2002) who closed the trail on his property. Turn left at the fence here and climb the hill turning left at the top to follow the trail along the ridge all the way back to the main trail. You would have passed this side trail on the way in, shortly after leaving the road. This ridge trail is mostly through woods and is almost all the way slightly downhill so it is easy going.
Instead of continuing from the dam another ten minutes along the trail, you can continue on the trail a short distance until you find a steep path that leads up the hill to the ridge trail: not that easy going, but you won't have to go all the way to the gate.
There used to be a farmer with chickens on Watson Road just north of the start of the trail. I don't know if he still has chickens. He gets upset (and rightly so) with dogs barking at his chickens, coming right at them in the coops through the woods. Get your dog on leash as you get back near the road or as you start in.