AllTrails
8.7
The most complete trail database in the US, and the reviews are recent enough to tell you whether a trail is muddy, closed, or busy this week.
Free tier is usable; the paid plan runs about $36 per year.

Desert hiking within city limits
Phoenix is an outdoor trip disguised as a metro area: three major desert preserves sit inside the city, and Sedona and the Grand Canyon are drivable.
It is a driving city. Plan the rental car first and everything else falls into place.
Flights
PHX sits 10 minutes from downtown with a light-rail connection.
Rental Car
Essential. Book early for winter high season.
Driving
Common from Southern California and Las Vegas.

Steep, exposed, and worth the 6am start.

The best introduction to Sonoran desert plants anywhere.

The signature Phoenix summit hike: 1,200 feet of gain with handrail sections.

Jeep tours, Cathedral Rock, and stargazing two hours north of Phoenix.
Two full days covers the essentials and three lets you add a day trip or an outdoor morning without rushing.
Check the getting-around notes above first: in some cities transit and walking beat a rental car outright, and in others a car is the only practical option.
The tools and providers that fit the way this trip actually works.
8.7
The most complete trail database in the US, and the reviews are recent enough to tell you whether a trail is muddy, closed, or busy this week.
Free tier is usable; the paid plan runs about $36 per year.
8.1
Budget shares much of the operational backbone of Avis at a lower daily rate. If your trip is flexible on pickup time, it is usually the cheaper of the two.
Typically $39 to $74 per day at major airports before taxes and fees.
Best used as a price check and a way to filter for genuinely refundable rates rather than as your only lodging search.
Varies by market; always compare against the hotel's direct rate.