Captive Hatching/Breeding
 

I've seen a few times on here and elsewhere captive bred animals from wild-caught parents, or captive hatched animals for sale. Is this legal, or does one need a permit to sell them? For example, if I caught a few specimens of Oregon's native Western Rattlesnake, got them to breed, and incubated the eggs, I'd have quite a few hatchling western rattlesnakes. Would I be able to sell them legally?

That depends on Oregon's state laws regarding native species.

What I would really like to see though is for you get a rattlesnake to lay eggs.

*facepalm* Oh right, duh..oviviparis. My bad, totally didn't think that through. But still, it amounts to the same question.

It still depends entirely on the state laws of Oregon, which I am unfamiliar with.
Some states have little or no restrictions, others restrict certain native species, and some restrict all native species. Still others allow keeping/breeding/selling native species with a permit.
You'll just have to research the laws of your state and/or contact the Oregon DNR for the answer as it applies to you.

Clay is correct.
For example: In Ohio there are two types of permits for native species: A $40 commercial propagating license or a $25 noncommercial propagating license. Both allow you to possess and breed native species, but only the commercial license allows you to sell them.
Just google Oregon native species laws and you should find it pretty quick.

According to the state laws, there is a list of animals, both native and non-native that are legal/illegal to sell or keep within the state. In the specific example of the rattlesnake, it's perfectly fine to keep one, but illegal to sell. So then....does that translate to it is illegal to sell it within the state? Or is it illegal to sell it to someone out of the state as well?

If they are illegal to sell in Oregon, and you reside in Oregon, I doubt it makes any difference where the buyer is located, you would still be in violation of Oregon state law by selling them period.