The snake that bit Jamie was likely supposed to be a Cottonmouth, which is prevalent throughout the Southern United States (Carolinas, Georgia, Florida, Alabama, Western Tennessee, Arkansas, Southern Missouri, Louisiana, and Eastern Texas).
The lashed wood frame that Roger uses to transport Jamie is called a travois.
Lizzy says that it is a good day for dyeing (referring to the fabric). This may be a nod to series developer Ronald D. Moore's past work on Star Trek: The Next Generation (1987). Moore is credited for writing the third season teleplay for Sins of the Father (1990) in which the oft-used Klingon saying "Today is a good day to die" is spoken for the first time.
When Jamie's leg gets really bad after the snake bite and they put leeches on it, they used a fake leg but real leeches. According to Sam Heughan, who plays Jamie, they attached a prosthetic leg to his own so that they didn't have to put the leeches on his real leg, but that the leeches did get close to his real leg.
In the early 1700s, bison were prevalent in North Carolina. However, through over-hunting and loss of habitat, their numbers dwindled. In 1799, Joseph Rice, an early settler of the Swannanoa Valley around Bull Creek, is known for shooting that area's last bison.