Hi,
A couple of us go up to Drumclog every couple of weekends, the site is out the back of strathaven on the A71, Directions would be to take the M74 to Junction 8, go stright through the round about and keep on going through Stonehouse then Strathaven after about 5-10miles you will see the sign post for Drumclog it's about 2 mins drive from there. The site is open every day of every week and it costs £20 per vehicle. The terrain is superb

It's got everything from forrest sections, river runs from a stream to about 5 foot depth, steep hills, large ruts, bogs etc etc. If you fancy coming out for a day we could meet up with you and show you around.
Both pictures were taken at the Drumclog site, plenty more pics where they came from. I'll post some later when i have more time.