Final answer:
The first commercial mine in the Indian Territory was a coal mine, which played a significant role in the region's economic development.
Step-by-step explanation:
The first commercial mine in the Indian Territory was a coal mine. Coal mining played a significant role in the economic development of the Indian Territory during the late 19th and early 20th centuries. It provided fuel for industry and railroads, and was an important source of income for many communities.
Learn more about Commercial mining in the Indian Territory