Went out for a "field day" today. I have been having issues obtaining N. americanus and decided to go out and at least taken inventory of local populations. I hit a state park in my area and was very impressed with the findings. Although the only adult specimens of the species I found in my fairly limited search were deceased, I found ample evidence of large pedes, including fresh fecal pellets, tell-tale chewed leaf litter, and TONS of juvenilles. I would not be embellishing to say that I saw easily 60 juvie N. americanus today, within only about a half mile's search range. I collected ten, which may seem like a lot for one location, but the population was so dense in this particular area that I don't think it would hurt much. I also picked up two flat-bodied 'pedes of an unknown species who were almost equally abundant.
I found it useful to "follow my nose" in pede hunting. Millipedes have a very distinctive odor, especially when you get a whole lot of them in one place, and I had almost unfailing success when I overturned leaf litter in areas where I smelled 'pedes. When I searched areas with no pede smell, I found - not surprisingly - no pedes! I haven't heard much about using smell when collecting in the field, so let me be one to say that I highly suggest utilizing this ever-handy sense!
What was very pleasing to me was the rich abundance of biodiversity. Spiders, centipedes, millipedes, isopods, beetles, worms, you name it - the leaf litter was positively crawling with it. I've been to other places where all you see lifting a log is some sluggish E. foetida and the odd pill bug, but every log seemed to harbor at least 5-10 different species at a glance. This is a very healthy ecosystem from what I can observe. Not only was the range of invertebrates impressive, but some indicator species such as salamanders and tree frogs were quite numerous. I counted within a stretch of maybe 200 feet on one hillside eleven fat, healthy salamanders representing two different species!
Overall, a very successful and pleasing day out. I'll edit later with some pics of some salamanders, a tree frog, and maybe even of the new 'pedes. 
Tags: Salamander Millipede N Americanus Narceus Americanus Field Collection