Traced in the Jordanelle Reservoir and retraced US-40 from Silver Creek Junction (I-80) to Heber City including the two or three interchanges. Interestingly Mayflower (the exit near the Jordanelle Reservoir) is signposted as if it is a town ("village" or "hamlet"), but Wikipedia doesn't say anything about it in its articles on Wasatch County and Jordanelle Reservoir.

Also retraced US-189 from Heber City south to Deer Creek Reservoir. Had to stop there because the road has changed since the aerial imagery and it is not completely clear which path the road takes (the old road is now a cycleway), so I might wait until I have a GPS trace of it. On the other hand there is some evidence of road construction which is a pretty good hint about the current road position.