The Southern Pacific rattlesnake is one of the most commonly known species of rattlesnakes that inhabits Camp Pendleton. It is one of three poisonous rattlesnakes on base. The other two include the California Red Diamond and Southern Speckled rattlesnakes. - The Southern Pacific rattlesnake is one of the most commonly known species of rattlesnakes that inhabits Camp Pendleton. It is one of three poisonous rattlesnakes on base. The other two include the California Red Diamond and Southern Speckled rattlesnakes.