That depends on which game you are playing, you need to be more specific :P
The route west of Viridian city. You can also get a mankey in rock tunnel
you have to trade from hg
In Pokémon HeartGold you can catch wild Mankey in Route 9 and you can only find them at Level 13 additionally you can find wild Mankey at Level 15 in Route 42, you can also trade with someone who was able to catch a wild Mankey in Pokémon Diamond, Pearl or Platinum after they had used the PokeRadar item.
no, only in Heart Gold.
You'll need to trade for it.
you should look at serebii.net for that answer.
In Route 3, 4, 23.
In Route 9, 38, and 39.
You can catch one at Route 225 or at Route 226 (using the PokeRadar).
He gets it in the episode "Primeape Goes Bananas." And he didn't catch a Mankey; while he first encountered it as one, he caught it after it evolved into Primeape.
You must trade because there aren't Mankeys in Crystal
Well you can't really catch them continuously but its rare to catch them