Which could be why there are no beavers at Grays Lake. No trees around.

Castor oil doesn't come from beavers. The castor sacs are...oh, heck, look it up. They're basically scent glands; the oldtime trappers used to use them as part of the bait they put on their traps.

Come to think of it, I don't know where castor oil comes from, unless it's from the castor bean.

Prepared mustard and brown sugar, or prepared mustard and orange marmalade, works very well as a sauce on carrots (and, I assume, parsnips).