C.R.S. § 38-36-159: Encumbrances must be registered.

The owner of registered land may mortgage or encumber the same by executing a trust deed or other instrument sufficient in law for that purpose, and such instrument may be assigned, extended, discharged, released in whole or in part, or otherwise dealt with by the mortgagee by any form of instrument sufficient in law for the purpose. But such trust deed or other instrument, and all instruments assigning, extending, discharging, releasing, or otherwise dealing with the encumbrance, shall be registered and take effect upon the title only from the time of registration.