What role did the mountain men play in westward expansion?

Mountain men played a crucial role in westward expansion by serving as guides, scouts, and fur trappers in the American West during the early 19th century. Their extensive knowledge of the terrain and survival skills helped pioneers navigate challenging landscapes as they moved westward. Additionally, mountain men established key trade routes and contributed to the mapping of the region, paving the way for future settlers and the development of the American frontier. Their interactions with Native American tribes also facilitated cultural exchanges and the fur trade, further influencing westward migration.