I've been spending the last three work days taking habitat measurements on two area rivers. I'm beginning to enjoy this kind of work. In a state famous for its lakes, where spending the weekend at the lake cabin is a way of life for many, rivers, especially smaller warmwater rivers, often get overlooked.
The Snake River flows some eighty miles from headwater streams in Aitkin County, MN, to its confluence with the St. Croix River east of Pine City. Although there are areas of whitewater near the mouth and again near where the headwater streams come together, the section I've been on is a wide, shallow, low gradient stretch. We traveled by flat bottomed boat with a small motor, but I found myself wishing I was floating lazily in a canoe.
There are cabins and houses scattered along the banks, more so in the area near Pine City, but much of the river flows through wild floodplain forest, with basswood, maple, oak, and an occasional white pine, the remnant of the vast white pine forest that covered this area until logging began 150 years ago.
This has been a dry summer, and the river is at a very low level. In some areas the river is a sand bar 100 feet wide with water barely six inches deep; occasionally we had to get out of the boat and drag it across these areas. However, debris piled on the banks and snags of grasses caught in tree branches spoke of spring torrents when the river level was about ten feet higher.
As I rode along in the front of the boat, watching the water ahead for logs and boulders, I was amazed at the water clarity. Lakes around here generally are not very clear, but the Snake River water was clear enough I could see down several feet. I saw an occasional smallmouth bass and suckers and redhorse. With water levels this low, fish are scarce in the sandy flats. Any available cover, such as a boulder, fallen tree, or bed of river pondweed, is utilized by fish. I have often read and preached the importance of instream cover for fish, but seeing the amazing numbers of fish that congregate in one log jam make the message clear. More habitat=more fish.
The fish weren't the only wildlife I observed. Small flocks of cedar waxwings flitted among the tops of trees. Great blue herons stood still in the backwaters. A flock of Canada geese flew overhead. Wood ducks and mallards splashed in wild rice beds. A bald eagle sored overhead. Shorebirds, perhaps spotted sandpipers, waded on exposed sand bars, enjoying the numerous tiny mussels and invertebrates. Mussels were abundant; I saw numerous live ones half buried in the sand, their siphons and gills exposed out of their shells. If mussels are an indicator of clean water, the Snake River is in good shape.
Our purpose in surveying the river is to assess the fish population, primarily the "game" fish; that is, walleye, northern pike, smallmouth bass, and channel catfish. However, I could probably spend days paddling the river, observing what I have described above, watching the glassy water slip by reflecting the blue sky, and not even wet a line.