To date, I have provided difficulty ratings only for hikes within the McDowell Sonoran Preserve. I used as a basis for the rating the key provided on the maps produced by the City of Scottsdale. The trail difficulty key there, however, relates to trails that are in my mind unclearly defined, and in a couple of cases I have differed in my opinion of the rating by one step harder or easier. I think this may be because the hike I have defined is not exactly the hike being defined by the city.

Roughly speaking, the hike levels correspond to the following trail descriptions:

 Easiest Easiest Essentially flat trail
Less than 2 miles
Paved or fine dirt trail
 Easy Easy Less than 500-foot elevation gain
Under 5 miles
Relatively level trail, involving no scrambling
 Moderate Moderate 500 – 1,000-foot elevation gain
Under 5 miles
Trail with loose and embedded rocks, involving no scrambling
 Moderately Difficult Moderately Difficult 1,000 – 1,200-foot elevation gain
5 – 6 miles
Small portions over 10% grade
Trail with loose and embedded rocks, scrambling unusual but possible
 Difficult Difficult 1,200 – 1,500-foot elevation gain
6 – 10 miles
Longer portions over 10% grade
Trail with loose and embedded rocks, some scrambling possible
 Extremely Difficult Extremely Difficult More than 1,500-foot elevation gain
More than 10 miles
Portions more than 15% grade
Trail with loose and embedded rocks, some scrambling possible