Mar Negro   Be the first to submit input for Mar Negro. If you have info on Mar Negro, Salinas County, Puerto Rico please submit it here to improve this web site.          These outdoors activities are available near Mar Negro.   Hiking Trails Near Mar Negro: Charco Azul Trail, Patillas County, 19 miles away   Whitewater Near Mar Negro: Rio de la Plata, -blank-County, 18 miles away       Class III-V(V+) - 5 miles long (Dam Section)