Fish Market Achievement
Sell 20 fish for cash (Campaign only).
Fishing locations are along the river edges and are shown on the map by a brown circle with a fish icon in the middle but you can just head to any area which has water. I'd also recommend you get the "Fish King" perk as this generally will help towards catching fish.
Before you start this though you'll need one of the four fishing rods. To obtain any of them, please refer to the "Hope County Master Angler" achievement.
- Basic Fishing Rod
- Natural Fishing Rod
- Wonderboy Fishing Road
- Old Betsy Fishing Rod
Once you have a rod and have located a fishing location, just fish away until you have twenty in stock. Remember that you can only hold a certain amount of stock for each fish so you'll need to change your location and your lure depending on the fish you're after.