Task: Explanation
Input (English): The Tongue River Dam (National ID # MT00002) is a dam in Big Horn County, Montana, a few miles north of the Wyoming state border. It impounds the Tongue River, creating the Tongue River Reservoir. Question: The Tongue River Dam impounds a  tributary that is approximately how many miles long? Answer: 265
Output (English):  It impounds the Tongue River, creating the Tongue River Reservoir.