Legal Question in Family Law in Utah

It may not rise to the level of custodial interference in the criminal sense of the word, but it appears as thought it's a clear violation of whatever court order you have granting you specific parent time rights. Under the provisions of UCA Section 30-3-36 whenever either parent intends to take the child on a vacation, they are required to give the other parent notice and provide the other parent with information about the travel itinerary, where and how the parent and child can be reached, and the contact information for any third party that may know where the child and parent can be contacted. Your ex should have provided that information before she left and her failure to do so would probably be a basis for you to take her to court on an Order to Show Cause asking the court to hold her in contempt.

Another issues is if she left the state and left your daughter in the care of her ex husband instead of you, she may have also violated your right of first refusal to watch your daughter while the mother was out of town. Without knowing a lot more about what language your court order contains, it's difficult for me to assess whether you have that right of first refusal and under what circumstances she may have been required to give you the first option to watch your child while she was out of town.