I use the 18-135 as a travel lens simply because it's so versatile. The 16-85 would probably be better for me, being wider and having better image quality, but not sufficiently so to warrant a replacement.
In addition to a zoom I (as good as) always bring a few primes when travelling; the DA15 is tiny and a wonderful landscape lens. I usually bring something like the FA43 and DA70, too. The key here is small size (as well as great image quality). The 55-300 has also given me some landscape shots I'm very happy with. Not all landscapes call for wide angle lenses.
You live just a twenty-two hour drive away, so feel free to drop by if you want to try some of my lenses