I soon realized that, without meaning to, I’d saved the best for last.

I’d paddled the river from Ridge Road (or whatever it’s called at that point) to Field’s Grove before, and had a grand time running culverts and flanking fallen trees.

This time, my father and I put in off Main Street in Dunstable, Mass. (that’s Gregg Road, in Nashua), and headed downstream. Upstream from there the brook broadens into a pond, surrounded by cow fields, so north seemed a better direction to explore.

We paddled for about an hour before finally hitting the first obstacle – a downed tree just before the stone railroad bridge. The river wound tightly through a meadow of swamp grass, occasionally nudging up close to the wooded hillocks.

It was drizzling all day, and though the mosquitoes managed to fly between the raindrops, we see surprisingly little wildlife, perhaps because two boats had gone ahead of us. We saw a great blue heron several times, and passed a painted turtle, a mallard and at least two exceedingly shy muskrats.

Unlike the lower stream, signs of civilization were few and mostly historic. The stream passes the remains of two old bridges, apparently from the days of horse-powered travel, before running underneath the spectacular dry-stone archway that once carried trains into Nashua.

What’s left of the railed runs between Main Street in Dunstable and the Pinebrook neighborhood off Ridge Road; one could leave a mountain bike at one end of the paddle, to retrieve a car from the other end.

Time constraints kept us from exploring either of the tiny tributaries we passed, or paddling beyond the railroad bridge, but I’m sure I’ll get to that soon enough.

The current moves along enough to help a boater out, but it's no great chore to make headway against it; even a solo canoeist could do it.