Check your payload, axle and tire ratings to be sure, but that weight is doable. That is a pretty long trailer to pull behind a half ton, however. You can do it and probably pretty safely if you set up your hitch properly and stay within all limitations, provided it's within your comfort zone. If you aren't traveling far from home you shouldn't encounter much in the way of challenging terrain.
Personally the limit where I'd want to move to a HD model is somewhere is probably in the 6-7000 range. To get to the higher end of the half ton tow ratings you see advertised have to move to the top engines and start adding towing and payload packages. I figure once you hit that point you can pay a comparable amount to get into an HD truck instead, and you've got a much more capable platform to work with. I see a lot more mountains than you, though, which is certainly a consideration.