SadieKate,
I had been all over the trails off of the Phil's trail head so I guess I am using the name for all those intersecting trails. I did see small mosquitoes when I took the trail that started off on the left near the john. It wound down and up, then turned right to a steady mild climb that took me past a tall volcanic outcropping. I stopped there to take a picture with my bike against the rock outcropping and saw them buzzing about there.

What looked like poison ivy was when I took the trail at the right till it turned left and looped around and up a good climb. Before the climb I stopped to have a granola bar and stepped off the trail with my bike. I did see the 3 leaf buggers but thought nothing of it...

I have not been down to the river trail.

Usually I just have problems like hit 'n run car damage, flooding out of campsites, being rescued in a hailstorm at Mt Rushmore and having tree branches fall and miss me by inches at national parks. I'm surprised that the rock outcropping didn't fall on me or something...