The correct choice is:
It was where the Mountain Men traded beaver pelts for supplies and where they had fun and games.
The Rendezvous was an important annual gathering for the Mountain Men in the early 19th century, where they met to trade their furs, particularly beaver pelts, for supplies, as well as to socialize, celebrate, and engage in various games and competitions. This event was crucial for the fur trade and for maintaining the community and camaraderie among the trappers.