The stretch of river from Maryhill to Rufus is very tricky to predict and can change several times throughout the day. There are two main causes for what could look like a great day out east to not materialize. One is that just a few degrees of wind angle is the difference between a great day and a frustrating day on the water at the sites along this stretch. With the high cliffs on each side of the river, if the wind does not line up with the river valley, it will pop in and out of the river valley, hopping over the cliffs, then popping back in, making for very up and down conditions. The direction of the wind is determined by the shape of the surface high pressure over the Pacific, and the placement of the surface low pressure in the Western Interior.
The second reason for poor quality wind along this stretch is an incoming large wave trough, which tends to lift surface winds up into the atmosphere, instead of keeping the winds down at the surface. This causes that gusty quality. This is why the second day of an incoming trough is often steadier than the first. And then of course there are many other factors.. but that doesn’t keep us from searching out the days when all the factors line up.