The ATM at cow lake is producing pretty good at the moment, dispensing 20 dollar bills as a rule. Easy to get to right when you walk in the store, I advise just walking in, not to drive in.
All kidding aside, the lake is accessible but when you get off the main trail on to the lake you will need 4x4. The fishing is great, the catching is slow to average, but you are going to have to find the holes. The average perch is probably 7 inch with the odd one being larger. You will spend the majority of the day drilling holes looking for the fish, rather than actually fishing. Hope this helps.