by 1893, from trail (n.) + agent noun from blaze (v.3).
Entries linking to trailblazer
trail n.
early 14c., "trailing part of a robe, gown, etc.," from trail (v.). The meaning "track or smell left by a person or animal" is also from 1580s. Meaning "path or track worn in wilderness" is attested from 1807. Trail of Tears in reference to the U.S. government's brutally incompetent Cherokee removal of 1838-9 is attested by 1908.
blaze v.3
"to mark" (a tree, a trail), usually by cutting of a piece of bark so as to leave a white spot, 1750, American English, from blaze (n.) "white mark made on a tree" (1660s), for which see blaze (n.2).