First Appearance: LIAB Text 19
This is the first mention of "rangers," but it probably denotes a forest-capable (or possibly other terrain-specific?) scout.
Real World References
A nod to the Ford Ranger, a pickup truck produced by the Ford company. Also, would seem to bear a resemblance to former U.S. president Gerald Ford. He is shown in a uniform resembling that of a park ranger.
The line "I have not sought this enormous responsibility, but I will not shirk it." is taken from the speech Gerald Ford gave shortly after being sworn in as president after Nixon resigned.