Over a dozen tarantula species can be found in the United States, mainly in the deserts of southern regions. Southeastern Colorado is home to a considerable population of Texas Brown or Oklahoma Brown Tarantula species that can be best spotted during their annual mating season beginning at the end of August and lasting through early October.
Comanche National Grassland in La Junta is the number one destination to spot tarantulas during their migration in Colorado. The park in the southeastern part of the state occupies about 443,764 acres (179,584 ha) of range lands. Be on the lookout for large, hairy brown spiders along Highway 109, between La Junta and Kim, or on Highway 71, north of Ordway. Vogel Canyon is the most popular hiking destination in the Comanche National Grassland. The peak tarantula viewing time in La Junta is mid-September. Spiders tend to be more active in the afternoon, especially in the last hour before sunset. Tarantula hawks in the air can give you a heads up on where to look for spiders.
Tarantula migration occurs when males reach adulthood at about 8 and leave their burrows in search for females. After a short mating season, a male tarantula typically dies before the arrival of winter. Females are luckier, having a lifespan of 20-25 years.