Final answer:
Mountain men and trappers prepared the West for other white settlers by establishing trade routes, engaging in fur trading, and exploring the terrain.
Step-by-step explanation:
Mountain men and trappers played a significant role in preparing the West for other white settlers. They established trade routes and relations with Native American tribes, which helped in facilitating future settlement and economic development. By engaging in fur trading and establishing trading posts, they created a network that eventually led to the establishment of towns and cities in the West. Additionally, their exploration and knowledge of the terrain paved the way for the migration of other settlers.