O. aeneus is found from within the Atascosa, Patagonia, and Pajarito mountains of southern Arizona in the United States,[6] through Mexico, to northern South America and Trinidad and Tobago.

Within Arizona, O. aeneus is exclusively affiliated with Madrean Evergreen Woodland communities and the upper reaches of adjacent semidesert grassland habitat.

It is usually encountered in trees or shrubs on open, steep, and grassy slopes, but is also associated with wooded canyons, especially those with abundant vegetation.

[7] O. aeneus is an extremely slender snake that reaches up to 1.9 metres (6.2 ft) in total length (including a long tail).

O. aeneus feeds mainly on lizards (mostly anoles), but also eats frogs, small rodents and birds.