Spending time with Rattlesnakes in eastern Idaho

A weak buzz and a slight movement drew my attention to a small clump of dried grass near Challis last weekend while I was hunting rocks with members of the Idaho Falls Gem and Mineral club.

“Snake!” I yelled to warn the others spread out across the hill. All stopped and closely observed the area before they worked their way to observe the large snake measuring close to four feet in length. The snake had a light green color and appeared to have recently shed its skin including the rattles, and had only two buttons that had started to grow.

The snake finally worked its way to a large sagebrush and disappeared down a hole to get away from the humanoids studying it. Later we located a smaller rattler sunning itself on a cliff high on a ridge about a half mile from the other one. This one was the normal brown color with a full eight button rattle that could be heard over 100 feet away.

The Western rattlesnake (Crotalus viridis) that is found in Idaho has three subspecies; the Prairie, usually found in Valley and Lemhi Counties; the Great Basin, located in the southwestern part of the state and the Northern Pacific rattlesnake that inhabit the Snake, Salmon and Clearwater River valleys. The one I encountered near Challis appeared to be a Prairie rattlesnake.

Locally this summer I have seen rattlers near Moody Creek, Ririe Reservoir, Medicine Lodge Creek, Leadore and Challis. While driving on a road between dry sage covered hills and an alfalfa field near Tendoy, north of Leadore, I also saw seven that had been become roadkill.

The males are usually larger than the females and they can mate any time during their active season with the young being born from August to October. The female will give birth to three to 12 young with the number usually increasing with the size of the mother. Most females do not produce litters every year.

Most of the food for these “pit vipers” are small mammals like mice, baby rabbits and wood rats, lizards and some baby birds. One snake I saw multiple times this summer near Medicine Lodge was curled up on a hole between two Common Nighthawk nests. It quickly disappeared each time I approached.

Each year the snakes shed their skin and their rattles growing a new “button” each time they shed. During this time, the snakes can be very dangerous as their noise makers are not developed and they cannot warn you. As one man told me, if you finds their skins leave the area, cautiously.

In Idaho rattlesnakes are protected with a possession limit on them and to harvest them a hunting license is required. A limit of four may be in your possession as pets or for your personal use.

Regulations state that up to six rattlesnake skins can be sold or bartered. Only the skins may be sold, not the entire snake as “wild game meat” may not be sold. In Utah, rattlesnakes are protected from being harvested.

Most of the rattlesnakes I have seen this year were in early June and early September because during these times they are active during the day by sunning themselves to regulate their body temperature. During the summer, they shade up during the heat and are more active at night. As fall approaches, they may den up with other species of snakes in crevices, rock piles or small caves and by November they are inactive and go into hibernation.

In all my outdoor activities, I have found that when I am in rattlesnake territory I keep my attention on the ground 10 to 12 feet in front of me. A four footer with soft growing buttons can be an alarming sight without its alarm going off.