Most of the trails to the south of Blackwood are to the west of the Greendale Trentham Road which is a prime area for 4WDing and motorbike riding. This creates some good opportunities for MTB riding as a lot of the trails get chopped up by these vehicles making the rides more interesting.

I have included a few rides here as examples but the best bet it just get a topographical map and start exploring. Out to the south east of Blackwood, the riding opportunities are limited to Morning Star Track, Deadmans Track and Kangaroo Track which are open for riding. There's a lot of gold mining history in this area as well so you can visit some of the sites as well.

Charcoal Track	A nice ride south along Telstra Track before trying out the motorbike half pipe along on of the creek valleys before heading home where you can pick from a stack of fire trails.
Kangaroo Track	One of the old 4WD tracks to the south of the river that has been closed off but left open for bike riders.
Morning Star	An easy run across the south side of town. If you want to spice it up, head on down Deadmans Track into the gorge.
Razzas	A short track which connects the St Erth Loop with Telstra Track and opens up some options for tieing some loops together (eg St Erth with Kangaroo Track across the Greendale-Trentham Road).
Telstra Track	A motorbike track that runs adjacent to the Greendale-Trentham Road. Nice rocky rutted surface with a gentle rise and fall to keep you entertained.

Blackwood	Click on link for map showing how to get there.

	There is a map of the general area (based on the Lerderderg Track which is part of the GDT) located to the right of the Blackwood Merchant store.