It’s almost September, which means one of Colorado’s most fascinating wildlife events is about to begin—the so-called Colorado tarantula migration. Every fall, hundreds of people head to the prairies of southeast Colorado hoping to witness large brown tarantulas walking across the grasslands.
Here’s the catch: it’s not technically a migration. What visitors are actually seeing is the annual tarantula mating season. Male tarantulas (scientific name Aphonopelma hentzi, also known as the Oklahoma brown tarantula) leave their burrows in late summer and early fall to search for females. Females remain hidden underground, while males roam the open prairie in their quest to reproduce.
When to See Tarantulas in Colorado
Male tarantulas take 7–10 years to reach maturity, and females even longer—10–12 years. For most of their lives, they stay close to their burrows, waiting for prey. But as days shorten and nights cool, males are triggered to wander in search of mates.
You might spot tarantulas as early as late August or as late as early October, but peak viewing typically happens during the last two weeks of September. Activity is influenced by temperature, wind, and time of day. The best chance to see them is about an hour before sunset, when males are most active.
Where to See the Tarantula Migration in Colorado
The prairies around La Junta, Colorado and other parts of southeast Colorado are prime tarantula-watching territory. County roads that cut across intact grasslands often provide excellent viewing opportunities. Drive slowly, pull over safely, and watch carefully—tarantulas sometimes cross the road.
Tarantula Festival in La Junta
La Junta embraces this annual wildlife spectacle with its Tarantula Festival, held the last weekend in September. The event features a parade, educational programs, and guided tarantula tours. It’s a family-friendly way to experience one of the most unique natural events in Colorado.
Want a Guided Experience?
If you’d like to go beyond the festival and explore the region with an expert who knows the best tarantula hotspots—as well as other southeast Colorado wildlife—consider joining us for our Southeast Colorado Wildlife Weekend in mid-September. It’s timed to coincide with the peak tarantula movement and offers a deeper dive into the region’s incredible biodiversity.