I went to take a look this afternoon. This would (embarrassingly) be a lifer for me. So my judgment is probably clouded as one would expect for someone in the 400's of life list who is lucky to add 10 a year without selfishly targeting my vacations for birds.
I studied it for 15 minutes as it moved from perch to perch (I was in my car on Clover Basin, Grandview and another residential road near the Blue Skies park.
I could never get a look at the underwings as it would fly away from my viewpoint and drop low immediately. I studied the legs for feathers and could not see any, but when I went back to study at the computer I see that those would be more subtle than what I was expecting with the name "rough legged".
But how about this tidbit. It perched in a short tree once in a remarkably thin branch. I thought that was odd and then later read on Cornell All About Birds that this is a behavior for roughies. Might it be true for a Harlan's too?
BTW this individual would certainly not be a dark-morph roughie.
Hopefully someone gets a pic and does whatever necessary to convince us all it is a roughie (photoshop is always an option ;-)
Ron Bolton
Berthoud