Towering at lengths over 7 feet, America’s biggest snakes command both awe and unease. While Florida’s swamps and the southeastern wilds are prime territory, these giants slither through forests, deserts, and grasslands across the country.
Meet the 12 largest snakes in the U.S.—creatures whose sheer size and ecological influence make them essential yet often misunderstood players in our ecosystems.
1. Green Anaconda (Eunectes murinus)
Length: Up to 30 feet
Location: Southern Florida
The green anaconda, native to South America, has found its way to the swamps of southern Florida. As the heaviest snake in the world, the green anaconda can weigh up to a staggering 550 pounds.
These massive constrictors are perfectly adapted to their aquatic environment. Their eyes and nostrils are positioned on top of their heads, allowing them to remain almost completely submerged while waiting for prey.
2. Reticulated Python (Malayopython reticulatus)
Length: Up to 18 feet
Location: Southern Florida
The reticulated python, native to Southeast Asia, is the longest snake in the world, with some individuals rivaling the green anaconda in length. With their distinctive geometric patterns and incredible strength, reticulated pythons are a sight to behold.
3. African Rock Python (Python sebae)
Length: Up to 16 feet
Location: Miami-Dade and Sarasota counties, Florida
The African rock python, the largest snake species in sub-Saharan Africa, has been captured in Miami-Dade and Sarasota counties in Florida. While a small wild population has been confirmed in a localized area of Miami, most of their presence in the U.S. is due to the exotic pet trade. (ref)
4. Eastern Indigo Snake (Drymarchon couperi)
Length: Up to 9 feet
Location: Southeastern United States
The eastern indigo snake, the largest native non-venomous snake in the United States, plays a crucial role in the ecosystems of the Southeast. Growing up to 9 feet long, this iridescent blue-black serpent is a gentle giant and an apex predator.
Eastern indigo snakes are often found in gopher tortoise burrows and help maintain balance in their habitats by controlling populations of smaller animals.
5. Eastern Rat Snake (Pantherophis alleghaniensis)
Length: Up to 7 feet
Location: Eastern United States
The eastern rat snake, a non-venomous species commonly found throughout the eastern United States, can grow up to 7 feet long. As skilled climbers, eastern rat snakes are beneficial for controlling rodent populations in various environments.
6. Burmese Python (Python bivittatus)
Length: Up to 18.8 feet
Location: Florida
Burmese pythons, native to Southeast Asia, have become an invasive species in Florida, where they have established a thriving population. The largest Burmese python ever found in Florida was caught in 2022, measuring an impressive 17.7 feet long and weighing 215 pounds.
7. King Cobra (Ophiophagus hannah)
Length: Up to 18.7 feet
Location: Occasionally spotted in Florida
The king cobra, the longest venomous snake in the world, is native to India and Southeast Asia but has been occasionally spotted in Florida.
While not established in the U.S., these impressive snakes can grow up to 18.7 feet long and are known for their distinctive hood and fearsome reputation. King cobras primarily prey on other snakes, including venomous species.
8. Amethystine Python (Morelia amethistina)
Length: Up to 28 feet
Location: Occasionally spotted in Florida
The amethystine python, also known as the scrub python, is one of the largest snakes found in Australia, Papua New Guinea, and Indonesia. These pythons are known for their iridescent scales and excellent swimming abilities.
9. Cuban Boa (Chilabothrus angulifer)
Length: Up to 19.6 feet
Location: Occasionally spotted in Florida
The Cuban boa, endemic to Cuba, is the largest snake in the Caribbean. While not native to the U.S., these massive boas have been occasionally spotted in Florida, likely as a result of the exotic pet trade.
Cuban boas can grow up to 19.6 feet long and are known for their unique hunting methods. They are the only snakes known to hunt in groups.
10. Central American Boa (Boa imperator)
Length: Up to 13 feet
Location: Occasionally spotted in Florida
The Central American boa, native to Central and South America, has been occasionally spotted in Florida due to the exotic pet trade. These impressive constrictors can grow up to 13 feet long and are known for their beautiful coloration and patterns.
11. Yellow Anaconda (Eunectes notaeus)
Length: Up to 12 feet
Location: Southern Florida
The yellow anaconda, native to South America, has been sighted in the swamps of southern Florida. While smaller than its green anaconda cousin, the yellow anaconda can still grow up to an impressive 12 feet in length.
These semi-aquatic snakes are excellent swimmers and are known for their distinctive yellow and black patterning.
12. Eastern Diamondback Rattlesnake (Crotalus adamanteus)
Length: Up to 8 feet
Location: Southeastern United States
The eastern diamondback rattlesnake, found in the southeastern United States, is the largest venomous snake in North America. Growing up to 8 feet long, these impressive pit vipers are known for their distinctive diamond-shaped patterns and rattles.
Eastern diamondbacks play a crucial role in their ecosystems by controlling populations of small mammals and birds.
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Davin is a jack-of-all-trades but has professional training and experience in various home and garden subjects. He leans on other experts when needed and edits and fact-checks all articles.