Yesterday, I was out bicycling in an area I’ve never been to before. I went down to Newberg, Oregon and then went out of town going south on Oregon Highway 219. I stopped and turned around just after crossing the Willamette River, where there was a historical marker (click on that image to get a readable picture).
Anyway, as the sign says, just east of that spot was a trading post built on a knoll. So I looked around that sign and saw… flat farm land. No knoll. (Sorry I didn’t take a picture, but my phone doesn’t have a camera.) So where is it? I don’t think it’s the hills you see in the distance to the left of the sign. Those are the southern extent of the Chehalem Mountains and don’t exactly correspond to what I think of as a knoll.
“In geography, knoll is another term for hillock, a small, low, round natural hill or mound.” – Wikipedia.
Remember, the flatland in the that immediate area makes Nebraska look like rolling hills. Even if that knoll was only a foot or two higher it would be obvious in winter when everything around it is underwater.
For those interested, the street view is here. It’s a little tough to judge because the fish-eye lens distorts things a bit.
The trading post was probably close to bank of the Willamette, so it would have been a little distance off. Going straight east from that point, the river is almost two miles away. In the picture I linked above, in the distance directly between the sign and the bush to its left I can maybe see a rise that I’d describe as a knoll. But I might be imagining that.
Zoom in between the bush on the left and the red and white stick. That blurry contraption is a center pivot irrigation boom. It sure looks like the first set of wheels is sitting a little higher than everything else. That’s all it takes to call it a knoll.
I sometimes wonder if standards were different back in the day. I got a tour of the Gettysburg battlefield once. The guide explained how the Union and Confederate troops were arrayed along Cemetery Ridge and Seminary Ridge, respectively. As I looked across the battlefield by first thought was “what ridges?”
Also as the sign says, the trading post was carried away by a flood.
The trees create knolls as the tree roots bind the river bank together and collect the sediments from the flood water and dust from the air, and biologicals from the decaying plant matter (and animals ? eg bird or bat poop ?)
But a flood can easily take away a knoll, especially if the trees are cleared to make the trading post…
Minor topographical feature aren’t likely to remain recognizable over the course of fifty years, much less 200. The spot that that knoll once stood might be on the other bank of the river at this point, be indistinguishable from the surrounding land, or even be a depression. Erosion is a powerful force given a little time.
OK, maybe you’re right. I had the idea the knoll would be more than just a foot or two above the level of the plain. Something substantial that would survive for quite a long time.
The thing is, this area is obviously (at least today, and I would expect back then) a flood plain of the river. And the river flooded a lot more than it does today, since it was totally uncontrolled. They’d want to get the trading post as high above that plain as possible while still being within easy reach of the river. But I guess they couldn’t find anything higher.