Yes, you can evict even if there not a lease. A tenancy can be established by a written or verbal agreement with the homeowner. A "tenancy at will" is a tenancy without a predetermined duration for the tenancy. Colorado has recently gone through a number of changes in recent years enhancing tenant protections, but even with those changes you can evict a tenant even if you do not have a lease.

You may be able to evict an unruly tenant if they are "unfit." In order for a tenant to be unfit, they have to have committed a “substantial violation.” For the purposes of Colorado eviction law, a substantial violation means any act or series of acts by the tenant that endangers people or property. For more information, read our legal guide "The Ultimate Guide to Evicting Bad Tenants."