Was the Potomac River clear when the first Europeans saw it?

The Potomac river drains a lot of area, and carries with it a lot of silt and debris. This has been true long before Europeans came to the Americas.

Granted it carried a lot less pollutants than today, with all the human agriculture and waste over the last few centuries, but it was never clear, at least in it's lower reaches. The stream that the Potomac starts out as, and many of it's tributaries at their origins are clear, but they still are today. In water, clear doesn't always equal clean.