Answer:
Ridge and valley Provinces
Explanation:
This particular region is a major producer for Rocks such as sandstone, shale, and coal coal-bearing beds in United States.
The geographical structure of the region in Ridge and valley Provinces were very difficult to reach (even using modern means of transportation). This terrain make it impossible for the company to hire the people from outside the area and let them commute to the workplace everyday.
This is why companies who want to utilize the resources that exist in this territory have to build a mining town there and make the workers live there during the operation.
