WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.
To Gateway Trailhead Take the 101 to the Princess Drive/Pima Road exit. Go north on Pima Road to Union Hills Drive. Turn right (east) on Union Hills Drive to Thompson Peak Parkway. Turn right on Thompson Peak Parkway and head south about 1/2 mile to the Gateway Visitor Center on the left. There's plenty of parking and nice facilities here.
Take 101 to Bell Road exit (by way of either FLW Blvd exit 39 arriving from the south or Pima/Princess exit 36 arriving from the north). Go East on Bell road 1.7 miles and turn left onto Thompson Peak Parkway. The Gateway is 0.7 miles on the right. (18333 N. Thompson Peak Parkway)
From PHX (I-10 & AZ-51) - 28.4 mi, 36 mins From TUC (Jct 1-10 & Grant) - 126 mi, 2 hours 6 mins From FLG (Jct I-17 & I-40) - 141 mi, 2 hours 33 mins