It was sheer luck that I found this skipper butterfly caterpillar. I was looking at a willow for insects, when I noticed a leaf pop up and then down. Lifting up the top leaf revealed this fat little caterpillar. I knew it was a skipper, but not which one. Thanks to Ross Layberry I now know it is a Dreamy Duskywing.

To see the skipper butterfly it becomes: http://www.pbase.com/laroseforest/image/105962398