This is just a wild guess, but wouldn't the phrases "tomahawk rights" and "tomahawked his land" refer to one marking his property boundaries by marking trees with a tomahawk?  And I believe that "preemption rights" refers to one's occupying a property -- i.e., a squatter -- before another person paid for and occupied the same said property.

Please correct me if I'm wrong!

Jean Spradlin-Miller