What did the french have to lose with colonist westward expansion

The richness of the area in the west side in minerals, resources and livestock and along with huge pieces of land were things which the french people had to lose.

Explanation:

The colonist were attracted towards the expansion on the west side because that side was rich in minerals, it had lots of gold and mining opportunities. The western area was rich in live stock and cattle and it provided huge opportunities to the people to earn their livelihood. The infra structure was also developed more in that area like the rail road or the communication which provided better supply of goods and services.