What do the boat owners at the dam charge if you book directly with them? And I assume they provide all the equipment (Bait, rod & tackle). And who provides the beer

? Also, what is the deal with fishing licenses? I understand you need a fishing license, (and there’s a 5 specimen maximum daily limit for freshwater fish of the same species, not that
I ever catch that much), but I don't know if they enforce it.
I've also heard there is good fly fishing for trucha (trout) in the mountain streams (and sometimes stocked ponds if you don't mind shooting fish in a barrel) between Cartago & San Isidro, particularly in the Rio Tapanti or Rio General.
Its not the mountains but I'm thinking of stopping in the Tortuguero area on my next trip and will report back on the freshwater fishing if I go. Of course they have the usual offshore sport fishing but they also have lake, river and rivermouth fishing for fairly reasonable rates. For example, Pura Vida Tours offering fishing for $40/hr per person, Ernesto Tours charges $60/hr per person and Caribeño charges $65/hr for up to 3 people (2hr min) or $400/day. For me personally, 2-3 hours out in the sun on the water sounds about enough (especially if, unlike ocean fishing, half your time isn't spent just getting in and out from the open ocean fishing spot).
The types of fish that you are likely to catch in the local rivers include: Black Bass, Rainbow Bass (Guapote), Croaker, Machaca and Cravalle Jack. Where the river empties into the sea you'll catch: Snook, Sabalo, Snapper, Jurel and Grouper. And of course in the ocean you'll get: Barracuda (not for eating but good for sport), Palometa, Tarpon, Mackerel and Tuna