I spent the day hiking and driving in Shenandoah National Park in Virginia. It is a beautiful park, and the weather was perfect. I was also treated to many insects going nuts on the flowers. The park has wonderful views of the area, including views that make it clear how the Blue Ridge Mountains got their name. I have identified the insects that I can. If anyone who happens to read this can identify or correct my identification, please contact me. I love to get the identifications correct. Edited to add: Thanks to Derek and friends on Twitter who have helped me identify the animals on this page!]
Your millipede is Narceus americanus-annularis-complex (http://bugguide.net/node/view/15012), one of our largest North American millipedes.