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Timber Rattlesnake

Crotalus horridus

Reptile · family Viperidae · order Squamata

  1. G1
    Critically imperiled
  2. G2
    Imperiled
  3. G3
    Vulnerable
  4. G4
    Apparently secure
  5. G5
    Secure

NatureServe global rank G4: apparently secure[2].

Updated October 30, 2026. Published by Humblebee.

Endangered Species Act
Not listed[1]
NatureServe global rank
G4 Apparently Secure[2]
Native in
31 states[3]
Longest recorded life
30.2 years[4]

The Timber Rattlesnake (Crotalus horridus) is a reptile in the family Viperidae[5]. NatureServe ranks it G4 (Apparently Secure) worldwide, and it is not listed under the US Endangered Species Act[2][1].

Conservation status

NatureServe gives the Timber Rattlesnake a global rank of G4 (Apparently Secure) and a US national rank of N4 (Apparently Secure)[2][6]. The IUCN Red List category recorded by NatureServe is Least concern[7]. It is not listed as endangered or threatened under the US Endangered Species Act in USFWS data checked on 2026-10-30[1]. NatureServe notes that its range, number of local groups and total numbers are probably still declining[8].

Status Value
Endangered Species Act[1] Not listed
NatureServe global rank[2] G4 (Apparently Secure)
NatureServe US rank[6] N4 (Apparently Secure)
IUCN Red List (via NatureServe)[7] Least concern
Total population (NatureServe estimate)[9] 100,000 to >1,000,000 individuals

Where Timber Rattlesnake lives

NatureServe lists the Timber Rattlesnake as native in 31 US states and territories, from Texas and Florida north to Minnesota, Wisconsin, Vermont and New Hampshire[3]. NatureServe ranks it as extirpated or possibly extirpated (gone from the area) in the District of Columbia, Maine and Rhode Island[10].

Alaska: not recordedAKMaine: extirpated or possibly extirpated, state rank SXMEWisconsin: native, state rank S2WIVermont: native, state rank S1VTNew Hampshire: native, state rank S1NHWashington: not recordedWAIdaho: not recordedIDMontana: not recordedMTNorth Dakota: not recordedNDMinnesota: native, state rank S2MNIllinois: native, state rank S2ILMichigan: not recordedMINew York: native, state rank S3NYMassachusetts: native, state rank S1MAOregon: not recordedORNevada: not recordedNVWyoming: not recordedWYSouth Dakota: not recordedSDIowa: native, state rank S3IAIndiana: native, state rank S2INOhio: native, state rank S1OHPennsylvania: native, state rank S3PANew Jersey: native, state rank S1NJConnecticut: native, state rank S1CTRhode Island: extirpated or possibly extirpated, state rank SXRICalifornia: not recordedCAUtah: not recordedUTColorado: not recordedCONebraska: native, state rank S1NEMissouri: native, state rank S3MOKentucky: native, state rank S5KYWest Virginia: native, state rank S3WVVirginia: native, state rank S4VAMaryland: native, state rank S3MDDelaware: not recordedDEArizona: not recordedAZNew Mexico: not recordedNMKansas: native, state rank S3KSArkansas: native, state rank S4ARTennessee: native, state rank S4TNNorth Carolina: native, state rank S4NCSouth Carolina: native, state rank S4SCDistrict of Columbia: extirpated or possibly extirpated, state rank SHDCOklahoma: native, state rank S3OKLouisiana: native, state rank S3LAMississippi: native, state rank S5MSAlabama: native, state rank S5ALGeorgia: native, state rank S3GAHawaii: not recordedHITexas: native, state rank S4TXFlorida: native, state rank S2FLPuerto Rico: not recordedPR
State presence as recorded by NatureServe[11].
Show state ranks (34 states)
StateRankMeaning
AlabamaS5Secure
ArkansasS4Apparently Secure
ConnecticutS1Critically Imperiled
District of ColumbiaSHPossibly Extirpated
FloridaS2Imperiled
GeorgiaS3Vulnerable
IllinoisS2Imperiled
IndianaS2Imperiled
IowaS3Vulnerable
KansasS3Vulnerable
KentuckyS5Secure
LouisianaS3Vulnerable
MaineSXPresumed Extirpated
MarylandS3Vulnerable
MassachusettsS1Critically Imperiled
MinnesotaS2Imperiled
MississippiS5Secure
MissouriS3Vulnerable
NebraskaS1Critically Imperiled
New HampshireS1Critically Imperiled
New JerseyS1Critically Imperiled
New YorkS3Vulnerable
North CarolinaS4Apparently Secure
OhioS1Critically Imperiled
OklahomaS3Vulnerable
PennsylvaniaS3Vulnerable
Rhode IslandSXPresumed Extirpated
South CarolinaS4Apparently Secure
TennesseeS4Apparently Secure
TexasS4Apparently Secure
VermontS1Critically Imperiled
VirginiaS4Apparently Secure
West VirginiaS3Vulnerable
WisconsinS2Imperiled

Habitat

NatureServe records the Timber Rattlesnake in hardwood, conifer and mixed forest and woodland, shrubland, rocky slopes, cliffs, wetlands and riparian (streamside) areas[12]. In the Northeast it lives in hilly forest with rock outcrops and ledges[13]. In the upper Midwest it is found on steep rocky bluffs with oaks[13]. In the central Midwest, the best habitat is a dry ridge with oak and hickory forest and some open areas[13].

Habitat types recorded by NatureServe[12]

Size, diet and lifespan

The Timber Rattlesnake is a carnivore[14]. Small mammals are its main food, and in the southern part of its range lizards are also common prey[15]. It sometimes eats birds and bird eggs[15]. NatureServe records a typical length of 189 cm (74 in)[16]. A typical litter is 9 young, and the gestation period is 135 days[17][18]. The longest recorded lifespan in captivity comes from AnAge, and it is a record and not a typical lifespan[4]. Females reach sexual maturity at about 2,555 days of age[19].

Trait Value
Typical length[16] 189 cm (74 in)
Longest recorded lifespan (AnAge)[4] 30.2 years (captivity)
Litter or clutch size[17] 9
Gestation or incubation[18] 135 days
Female maturity[19] 2,555 days (about 7.0 years)
Food habits[14] Carnivore
Migration[20] local migrant

When to look for it

The Timber Rattlesnake is recorded by NatureServe as hibernating or aestivating[21]. NatureServe records it as active by day, at night and at dusk and dawn[21]. It is a local migrant, moving between winter dens and summer habitat[20]. In Virginia, New York and Connecticut, snakes come out in April or May and head back to dens in September or October[22]. Observation records on GBIF are highest in June, July and August, which shows when people report it and not how many animals there are[23].

January: 59 recordsJanFebruary: 60 recordsFebMarch: 269 recordsMarApril: 1,036 recordsAprMay: 2,321 recordsMayJune: 2,537 recordsJunJuly: 2,486 recordsJulAugust: 2,464 recordsAugSeptember: 1,803 recordsSepOctober: 986 recordsOctNovember: 185 recordsNovDecember: 40 recordsDec
US observation records on GBIF by month, all years. The three months with the most records are highlighted. Records show when people look and report, not how many animals there are[23].
Show records by month
MonthRecords
January59
February60
March269
April1,036
May2,321
June2,537
July2,486
August2,464
September1,803
October986
November185
December40

Where to see it

National Park Service species lists record Timber Rattlesnake as present in 32 park units[24]. Present means the park has a confirmed record, not that sightings are common.

And 8 more park units.

States with the most GBIF observation records: Pennsylvania, North Carolina, Alabama, New York, Georgia[25]. These counts follow where people look and report, not population size.

Safety around this animal

These tips are quoted in summary from official agencies. We add no advice of our own. Follow local rules and the agency pages linked below.

From CDC / NIOSH

  • CDC lists rattlesnakes, copperheads, cottonmouths and coral snakes as the venomous snakes of the United States.
  • After a bite, get emergency medical care as soon as possible, and do not drive yourself.
  • Keep the bitten limb in a comfortable, neutral position, take off rings and watches before swelling starts, wash the bite and cover it with a clean dry dressing.
  • Do not cut the wound, suck out venom, or use a tourniquet, ice or water immersion. Do not handle the snake, even a dead one.
  • If you can do it safely, take a photo of the snake from a distance to help with identification.

Source: CDC / NIOSH[26]

Questions people ask

Is the Timber Rattlesnake endangered?
It is not listed as endangered or threatened under the US Endangered Species Act[1]. NatureServe ranks it G4 (Apparently Secure) globally[2].
Where does the Timber Rattlesnake live?
NatureServe lists it as native in 31 US states and territories, mostly in the East and Midwest and south to Texas and Florida[3]. It is ranked as extirpated or possibly extirpated in the District of Columbia, Maine and Rhode Island[10].
What does the Timber Rattlesnake eat?
Its main food is small mammals, and lizards are also common in the south[15]. It sometimes eats birds and bird eggs[15].
How big is a Timber Rattlesnake?
NatureServe records a typical length of 189 cm (74 in)[16].
When is the best time to see a Timber Rattlesnake?
Observation records on GBIF are highest in June, July and August[23]. These records show when people report the snake, not how many animals there are[23].

Facts and sources

  1. Timber Rattlesnake is not listed as endangered or threatened under the US Endangered Species Act in USFWS ECOS data (checked 2026-10-30). USFWS ECOS
  2. NatureServe global conservation status rank for Timber Rattlesnake: G4 (Apparently Secure). NatureServe Explorer
  3. NatureServe lists Timber Rattlesnake as native in 31 US states and territories: Alabama, Arkansas, Connecticut, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Minnesota, Missouri, Mississippi, North... NatureServe Explorer
  4. Maximum recorded lifespan in AnAge: 30.2 years in captivity. This is a record, not a typical lifespan. AnAge
  5. Timber Rattlesnake (Crotalus horridus) is a reptile in the family Viperidae, order Squamata. NatureServe Explorer
  6. NatureServe national rank in the United States: N4 (Apparently Secure). NatureServe Explorer
  7. IUCN Red List category as recorded by NatureServe: Least concern. NatureServe Explorer
  8. NatureServe notes on trend for Timber Rattlesnake. NatureServe Explorer
  9. NatureServe estimate of total adult population (global, as a range): 100,000 to >1,000,000 individuals. NatureServe Explorer
  10. NatureServe ranks Timber Rattlesnake as extirpated or possibly extirpated (SX or SH) in: the District of Columbia, Maine, Rhode Island. NatureServe Explorer
  11. NatureServe state ranks for Timber Rattlesnake (map and table on this page). NatureServe Explorer
  12. Habitat types NatureServe records for Timber Rattlesnake: Forest - hardwood, Forest - conifer, Forest - mixed, Woodland - hardwood, Woodland - conifer, Woodland - mixed, Shrubland/chaparral, Bare rock/talus/scree, Cliff, Scrub-shrub wetland, Forested... NatureServe Explorer
  13. NatureServe notes on habitat for Timber Rattlesnake. NatureServe Explorer
  14. Adult food habits recorded by NatureServe: Carnivore. NatureServe Explorer
  15. NatureServe notes on food for Timber Rattlesnake. NatureServe Explorer
  16. Typical length recorded by NatureServe: 189 cm (74 in). NatureServe Explorer
  17. Typical litter or clutch size in AnAge: 9. AnAge
  18. Gestation or incubation period in AnAge: 135 days. AnAge
  19. Age at female sexual maturity in AnAge: 2,555 days (about 7.0 years). AnAge
  20. NatureServe migration category for Timber Rattlesnake: local migrant (populations can differ). NatureServe Explorer
  21. Adult activity patterns recorded by NatureServe: Hibernates/aestivates, Circadian, Diurnal, Nocturnal, Crepuscular. NatureServe Explorer
  22. NatureServe notes on phenology for Timber Rattlesnake. NatureServe Explorer
  23. GBIF observation records of Timber Rattlesnake in the US by month (chart on this page). GBIF
  24. NPSpecies park lists recording Timber Rattlesnake as present (list on this page). NPS NPSpecies
  25. US states with the most GBIF observation records of Timber Rattlesnake: Pennsylvania, North Carolina, Alabama, New York, Georgia. Record counts follow observer effort, not population size. GBIF
  26. Safety guidance from CDC / NIOSH. CDC

Status, range and habitat come from NatureServe Explorer (CC BY 4.0) and USFWS ECOS at the snapshot date. Listings change by federal rule. State lists are where NatureServe records the species, not a promise that you will see it there. Never name a place smaller than a state. GBIF and park records count observations and checklists. They show where and when people report the species, not how many animals live there.

NatureServe. 2026. NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org. (Accessed: October 30, 2026). Licensed under CC BY 4.0; SpeciesFacts selected and summarized it.