I don't think conservation is a "dead end." I think it's actually a high-growth field.
I don't know if you'll ever get rich going into it, but if you end up going into a field like environmental engineering, as Joseephuss mentioned, then there's probably good potential to make some money doing that.
But most of all, do something that you enjoy and will love doing. There's nothing worse than finding yourself in a field you hate. No amount of money is worth that.
I ended up majoring in English Lit, because I knew I'd really enjoy it... even though it has a rap for being a soft discipline and a field without much of a future outside of teaching. Anyway, I ended up finding a profession that took advantage of that background... a job I didn't even know existed when I was in college... and I couldn't be happier.
So follow a path that you know will make you happy, and then worry later about finding a good job that fits your talents and aptitudes. There are so many professions out there that you probably don't even know about, but will reveal themselves once you're in that field.
Hopefully that all makes sense.
Good luck.