Here, we have western red cedar (WRC) (and hemlock, which is only used for framing houses and as pressure treated wood. If it gets wet, it rots, unless treated). Has this hemlock been kiln dried? Just curious, as it affects pitch and insects...
I also have a sawmill, and have cut a few logs - hemlock, doug fir, alder, broadleaf maple, cherry, even tried the evil cottonwood ( AKA black poplar ).
WRC is unmistakable - it is usually very dark red in color, and very aromatic. I have cedar stumps here that were left over from logging 90 years ago, and if you cut into one, it *still* smells of, well, cedar, and is usually still structurally very strong once you get past the exterior.
At the mill, WRC sells (even in these times) for about double of what they pay for doug fir, and alder is just above doug fir in prices these days.
Personally, I wouldn't waste my time with hemlock for any outdoor use, it just doesn't last when it gets wet. I've not used it for hive bodies, so it may pan out for you if you seal the wood (couple of coats of paint) - my deck is over 20 years old, and the decking is 2x6 clear fir and is in pretty good shape. The railings are 2x4 hemlock, and you can push a finger halfway through them. The siding on the house is T&G rough cut cedar, and looks like the day it was milled, which was back in 1983.
Just a few points to ponder...