Local advocacy groups and volunteers have removed trash and more than 23,000 car tires from the Bronx River over the years, but the river's dirty reputation is becoming a thing of the past, according to one group of students from Columbia University. 

They spent the day gathering discarded bottles and cans along the river; even taking a canoe ride to tour the revitalized waters.

Their ultimate mission is to bring the waterway back to its original state.

They say wildlife continues to come back to the Bronx River, and they are beginning to see animals that have not been seen in the area for years, like the beaver and muskrat. 

However, the students say there is still more work to be done.

They encourage everyone to help clean up along the riverway so that it may continue to undergo a revitalization.