How does one Attain a Dynamite License?

Go north looking for Redd - you will come across some loggers who need help to unjam a river - all you have to do is beat the bandits and blow up the rocks that are blocking the river - when you do this you will get your dynamite license and you will get 3 gunslingers -- HINT: don't forget to go to the street sign by the trading post to get a note from Redd!