Final answer:
Fur traders and middlemen moved to new western regions due to the depletion of fur-bearing animals in the east and the abundance of trading opportunities in the new territories.
Step-by-step explanation:
The fur traders and middlemen moved west to new regions primarily due to the depletion of fur-bearing animals in eastern regions. As European settlements expanded, wildlife in the east was over-hunted, causing a significant reduction in the fur-bearing animal population. This pushed the fur trade industry to seek new areas where these animals were still abundant. Additionally, competition with other fur traders in the east also drove them to seek less competitive markets.
Another fact contributing to their westward push was the abundance of trade opportunities in the west. With the west largely unexplored and full of natural resources, fur traders had the chance to establish new trading networks with both indigenous peoples and other European traders. The relationships formed often led to alliances and the exchange of goods such as guns, cloth, and metal cookware for valuable furs.