Before the weather shifted back to wet, I had a venture up the Skagit Valley in an area of old river channels, old river terraces and a dissected alluvial fan. One of the old river channels on what is now a terrace above the river flood plain was ice covered.
The lower end of the channel showed that water had been flowing out of the channel prior to full freeze up. The valley in the background is a tributary stream valley to the Skagit.
Stumbling about a forested flood plain with lots of water has its pleasures; the above observations were secondary to my field excursion. To get a better handle on the flood plain, old channels, terraces, and the creek a view of a DEM of the area clarifies understanding of the landscape.
DEM of Skagit Valley
Red line roughly marks the outline of the alluvial fan of the creek and blue marks the creek route.
Skagit River is on the north side of the valley on this river reach
The wide meanders and old channels of the Skagit are readily visible. What is also apparent is that the Skagit River took a few bites out of the northern, distal part of the creek's alluvial fan. A small secondary fan has formed where the creek encounters the old river channel. A stream course change on this secondary fan has directed the creek into a slightly different route now through the trees shown in the image above.
I did not mark the Skagit flood plain the above image. Most of the meander bends and old channel traces on the south half of the valley are now well above the flood plain level and are level terrace areas bound by flood plain abandoned channels or in places the river itself. This indicates that though the river has a meander component in this reach, it has still been down cutting. This reach of the Skagit is a broad section of the valley that continues downstream to the Sauk River. Below the Sauk the river enters a much narrower reach where it is incised down through a thick section of glacial sediments including a high terrace with kettles.
DEM of Skagit - Sauk confluence
The narrow reach to the west cuts through glacial sediments
Upon my return from exploration of the flood plain my new friends on the terrace above the flood plain came over to greet me.