Pueden and quieran

Can we talk about this phrase? Y no sólo dijo que ustedes pueden ir a pescar cuando quieran And she didn't just say that you guys can go fishing whenever you want. It appears that pueden is third person plural present tense indicative while quieren is third person plural subjunctive mood.

If I were to speculate a guess as to why quieran is used (third person plural subjunctive), it would be that the latter half of the sentence is discussing something that might happen. In fact, I think just the sentence "you can't go fishing whenever you want" = "no se puede ir a pescar cuando quiera". In English we have a lot of words that give different moods but we don't have special conjugations that are triggered from that. This is what makes it hard for us English speakers to learn subjunctive usage. In the sentence above, the keyword is the "whenever".