Bryson writes this novel in 1st person point of view using a casual and enthusiastic tone. This tone fits the audience - Bryson is not writing for the expert hiker, he is writing for the general public.
In order to help his audience experience his trip, Bryson uses sensory language. The example below uses words like "click" and "snuffling" to call upon the sense of hearing:
There was a sound of undergrowth being disturbed--a click of breaking branches, a weighty pushing through low foliage--and then a kind of large, vaguely irritable snuffling noise.
To assist in the description, Bryson also uses similes:
Once a skunk had come plodding through our camp and it had sounded like a stegosaurus.
Instantly every neuron in my brain was awake and dashing around frantically, like ants when you disturb their nest.
Also, Bryson employs humor. The examples below demonstrate this. In the first, it is an obvious rhetorical question (certainly the bag has a bottom). In the second, it is exaggerated comparison - the simple pancakes not versus a bear, but versus a "ravenous..).
"Are you saying, Dave, that I pay $250 for a pack and it doesn't have straps and it isn't water proof? Does it have a bottom in it?"It was a perfectly respectable appliance for, say, buttering pancakes, but patently inadequate for defending oneself against 400 pounds of ravenous fur.