We searched high and low for good directions and maps for driving to the Puerto Penasco Mayan Palace. Finally, Jackie one of our owners (a Phoenix native) gave us good directions and we got some good maps.
Starting from I-10 - west of Phoenix From I-10, head south on Highway 85. On 85 you will go through Gila Bend. You need to carefully watch for the 85 signs as you wind through the town. It's a decent size town with food and gas stations. - the other towns are very tiny: Ajo, Why and Lukeville (sits just north of the border).
It's a very small border heading into Mexico. People are very rarely stopped. It's closed from midnight to 6AM. We usually fill up with gas at a station just north of the border. After crossing the border you will be in the town of Sonoyita, Mexico. Again you need to carefully watch for M-8 signage (a Mexican federal highway). I believe at this point you start to see signs directing to Puerto Penasco. It's now about 60 miles to Puerto Penasco.
Continue south on M-8. Once within the limits of Puerto Penasco (a couple of miles before the main town), you need to look for a sign directing to Caborca. There is Mayan Palace signage at the exit. The exit is on the right but it will take you back across M-8 to the other side. Drive for about 9 miles. This is a 2 lane paved road.
At kilometer #24 is the entrance to the Mayan property (good signage). The entrance is on the right and there is a guard house where they will check reservations. Drive another 9 miles (not very scenic, a lot of dirt) and you'll be at the resort (another gate house). This road is greatly improved although not paved (at this point). But it is now well-lit at night.
If the Caborca turn-off is missed you would just continue south into the town of Puerto Penasco and go east on Fremont y o Ignacio Allende (traffic light) to the resort. The Caborca route cuts a corner and saves time getting into the resort and leaving for home. But Fremont will be the most direct route in and out of town while at the resort.
Total travel time is about 3 1/2 hours. As you can imagine return to the US is very strict at the border and there is a second check point about 15 miles north.