Towards the end of April the rattle snakes start to come out but if you stay on the trails and keep your dog leashed it’s unlikely you’d have any problems.

Yes! Especially in the springtime this time of year. The snakes are definitely out in force. It's their property so leave them alone of course.

There are rattlesnakes across the west below 9000 feet as soon as it stops freezing at night

Hello Jay, Yes, Arizona has snakes in April, which is part of rattlesnake season that runs from March to October. Rattlesnakes are most active during the day in the spring, and some say they are most active in April. In the summer, they are most active at night, and during the hottest months, they are most active at night. Most bites occur between 4–10 PM in the spring, summer, and fall, and between 10 AM–4 PM in the winter.

I never "worry" about rattlesnakes. Sometimes I see them hiking. They could be around. If you are with your dog and the dog is on a leash you will be fine as will your dog