Final answer:
Montana is the state that features the Yellowstone River, Missouri River, Fork River, and Powder River. The Missouri River, one of these rivers, was explored to determine its potential as a trade route. The Yellowstone River is also celebrated in art, evident in Thomas Moran's painting.
Step-by-step explanation:
The state that has the Yellowstone River, Missouri River, Fork River, and Powder River is Montana. The Missouri River is historically significant, having been explored during missions to map the potential water routes for commerce. A mission was established to explore the Missouri River and its tributaries to assess their potential for providing a water passage to the Pacific Ocean, which would have great implications for trade.
Artist Thomas Moran produced a painting of the Grand Canyon of the Yellowstone, capturing the Yellowstone River's awe-inspiring beauty. This artwork took six years to complete and was eventually purchased by the federal government. The painting emphasizes the Yellowstone River's power and the grandeur of its surroundings, illustrating its significance both in nature and culture.