This is the annual Tor de 50 put on by AZ Endurance Series, connecting the upper 50 year area with the Tortolitas. It's about 54 miles total with over 5500 ft. of climbing. It is a self-supported endurance ride. GPS recommended.
This is not a SAMBA sponsored event. You need to sign up with AES here: https://rockyroad5050.wordpress.com/tucson/
A few of us are planning to do a bit shorter route, looping around Honeybee and avoiding the extra climbing in the Tortolitas, but still a fairly long ride.