Drive east out of Petawawa on the main road, through Pembroke and then take 21 to Beachburg. Hang a left on Robertson Dr and then a left on Power Rd the put-in is at the end of this road.
Get out to 17, take 17 east past Pembroke, and left on 24. Take 24 to the end, hang a right then left on 21. Follow the above directions to Beachburg and the put-in.