Where do you want to live after law school? The answer to that question should steer you towards a few law schools. With a 3.16/160 you can get into some good regional schools. Most of your internship/clerkship/summer associate opportunities will be within the school's immmediate region, and it's highly likely that your first job will be, too. That's just the way it tends to work. Think about where you'd like to live for three years, and likely practice for 3-5 additional years after school.
Lewis & Clark and Vermont have good enviromental/natural resources programs, and are probably doable with your numbers. I seem to remember that Houston has a good energy law program. My understanding is that natural resources law is one of the few areas (along with tax and maritime) where an LL.M is preferred and sometimes required.
A note on specialty programs: very few law schools have the kind of national reputation that will land you a job based on pedigree alone. Apart from those few elite institutions, all law schools are regional. Some small regional schools which are not otherwise notable have very good specialty programs. It is important to understand, however, that regardless of specific programmatic rankings these are still regional schools. The big firms and federal agencies (like EPA) will still prefer grads from top ranked schools with bigger overall reputations.
Bottom line: if you really want to live in NYC, for example, you're probably better off going to a local NY law school than to a regional school in some other part of the country that happens to have a specific high-ranked program. No matter what US News says about a particular program, local grads who have had the opportunity to network for three years will have a distinct advantage over an out-of-towner. I've personally witnessed this time after time.
It's just my personal opinion, but I think that these categories of sub-rankings are a bit misleading. This doesn't mean that you shouldn't go a particular school, it's just something to consider when you're preparing to spend three years of your life and (probably) lots of money. With your numbers, though, you can get into some good schools. You'll be fine!