Check the water level:

USGS Current Streamflow at Vanceboro

If you are looking for testimonials and descriptions to convince you that the river is beautiful, quiet, fun, and safe; that the fishing is great; or that its practically ridden with moose, bald eagles, osprey, and beavers, there are plenty of websites to be found that will do just that. And it's all true.

Here's a good one:

GORP

Topo maps and aerial views:

Topozone.com

St. Croix International Waterway Commission

Forgotten Waters