Into The Wild

Expeditions to the far corners of the Earth, and the horrors found there, are a foundational part of both the Mythos and pulp adventure.   If  you have any interest of the actual gear and equipment used in period I would heartily recommend Stuart Edward White's "Camp and Trail" from 1906.  It's a well-written introduction to roaming the wilds that includes an thorough overview of vintage-era camping equipment.  That includes a very detailed look at running horse and mule trains.

The biggest lesson to be learned from the book is that little, if anything,  has actually changed.  Take a rambler from the late 1890s or early 1900s and plop him down at a trailhead today and he'd easily recognize every piece of equipment in use.  The only significant innovations have been the development of artificial fibers, which cut the weight of gear significantly, and tents supported by flexible spars under tension.