What it means
When a Scottsdale local says rattlesnake, they almost always mean the Western diamondback, Crotalus atrox: a heavy, gray-brown snake with diamond blotches down the back, a black-and-white banded tail ending in the rattle, and a habit of lying across trails and under patio furniture from spring through fall. When they say Mojave, usually with a slight drop in voice, they mean Crotalus scutulatus, the greener, similar-looking species whose venom gave it the nickname “Mojave green” and a reputation that outruns the record. Arizona has 13 species, more than any other state, and the McDowells hold at least four.
The vocabulary around them is practical. “Snake season” is roughly March through October. “Snake fence” is the fine mesh at the bottom of a view fence. “Aversion training” is what you buy for a dog that hikes. The desert wildlife field guide makes the point that visitors ask about rattlesnakes while residents worry about bees; this page is the longer version.
Where you’ll meet it
On Preserve trails at dawn and dusk from March to October, in garages and pool equipment areas in the foothill neighborhoods, under the shrubs of any yard that backs onto a wash, and in the dogs guide, where the leash rule stops being a suggestion.
Where the word came from
Rattlesnake is plain English for the one thing no other snake does, and the word is as old as English settlement in the Americas. The species names are descriptions too. Atrox is Latin for savage, which the diamondback does not deserve, and scutulatus, “with small shields,” refers to the Mojave’s large head scales. Diamondback names the pattern; Mojave names the desert where the second species was first described, though it ranges across the Sonoran as well. Spanish speakers say víbora de cascabel, the bell viper, which is a better name.
What locals actually need to know is behavior, and here the record is consistent. Rattlesnakes are ambush hunters that would rather not be found. They coil, hold still and rattle when something large comes close; they strike when cornered, stepped on or handled. Arizona Game and Fish and the Park Service say the same thing: most bites happen to people trying to catch, kill or move a snake, and the rest to hands and feet put where eyes have not looked. The diamondback is the most-seen snake in the Preserve because it is big, common and fond of trails, which hold the day’s heat.
Timing runs on temperature. From late October to mid-February the snakes are in winter dens or staging near them and encounters are rare; a warm February brings them out early, which is why Game and Fish issued its 2026 warning on February 27. Spring and fall are peak, and in the heat of summer they move at night and rest by day, so a July hiker on the sunrise schedule meets more of them than a noon one.
What it is not
The gopher snake, which is the snake most often killed as a rattler in Scottsdale: long, tan, blotched, no rattle, and a bluffer that hisses and shakes its tail in dry leaves. It eats rodents and is worth having. The coachwhip and kingsnake are not rattlers either. If you cannot see a rattle and a wide triangular head, leave it alone anyway; the rule works for every snake.
The fine print
The Mojave’s reputation rests on venom chemistry. Populations carry one of two venoms: Type A, with Mojave toxin, a presynaptic neurotoxin, or Type B, which lacks it and does the tissue damage typical of other rattlesnakes. Type A is the one in the folklore. Yet reviews of large Arizona bite databases have found no reports of neurotoxic respiratory failure or paralysis, which suggests the danger has been overstated; the practical difference is nil, because the antivenom used in Arizona hospitals covers every local species and identification is not required for treatment. Tail-band rules of thumb exist, with the Mojave’s bands lower in contrast and the segment next to its rattle yellow rather than black, but removal professionals warn that both species vary enough to fool anyone.
The first-aid list has not changed in decades and still gets ignored. Do: call 911, keep the person still and calm, remove rings and watches before swelling, keep the limb neutral, mark the swelling line with a pen and the time. Do not: cut, suck, ice, tourniquet, drink, or use any device sold for the purpose. The Arizona Poison and Drug Information Center answers 1-800-222-1222 around the clock.
Prevention at home is fencing and housekeeping. A snake fence is 36 inches high, 30 at the absolute minimum, of quarter-inch or finer mesh, sealed at every gate and drain, with the yard kept clear of debris, standing water and the rodents that draw snakes in. Dogs are the usual victims; most bites happen off leash with the dog’s nose in a bush, and the combination of a leash and professional aversion training is what the trainers and the removal companies both recommend. In the Preserve, rattlesnakes are protected and the city asks you to report, not remove. On the trails in the hiking guide, the whole rule fits in four words: watch your feet and hands.