Legal Question in Family Law in Colorado

Generally yes, unless there is some reason the father should not be with the children (i.e., he is a threat to their physical health or emotional development). The grandparents also do not have standing to assert general custody rights unless the child has been living with them for more than 6 months, and even then the father's testimony is given "special weight" over a non-parents as to "custody." Grandparents can file for grandparent visitation in Colorado though, which might be the place to start. You can call me if you would like to discuss this further (and the case is/would be in a court within an hour of Boulder). I hope this helps.