Hi! poison baits available in Colorado include zinc phosphide baits, and those containing an anticoagulant poison, but they are a risk to non-target species like domestic animals and other types of wildlife and they are restricted use for those reasons. 

Another alternative is fumigate burrows with aluminum phosphide fumigants (also restricted use) and a potential threat to non target species. The USDA cartridge is another alternative and the only non-restricted use of these products. Depending on your location, your local Conservation District may have carbon monoxide machines available for rental as well (Like this one: https://conservation4you.org/about/perc-equipment-leasing/ ).

Best,

Karla M.