New Mexico Ridge-nosed Rattlesnake (Crotalus willardi obscurus) is a small (0.62 m total length) rattlesnake that is only found in the mountains of far southwestern New Mexico, neighboring Arizona, and northern Mexico. They live primarily at high elevations in pine-oak woodlands, pine-fir forests, and pinyon-juniper woodlands. Their gestation period is 13 months, at which point they give birth to live young.