Sawfly larva / Trichiocampus viminalis

A friend called out my name on a recent walk to show me this tiny, vibrant yellow caterpillar. Thanks so much, Aileen, for noticing this little creature and for letting me know! It was crawling along the railings of a small, wooden bridge that we crossed on our walk from Mallard Point and along the east side of the Bow River. I took several photos, but only a couple were sharp enough, the rest total blur. John, I hope your shots came out better than mine, LOL!

Thanks to babyruthinmd for suggeting this is a Sawfly larva, and to Art (LeapFrog!) for his link to "Sawfly larva" "Trichiocampus viminalis". This help with ID was much appreciated.