Can I take my 6 year old daughter out of state for vacation without my ex’s written consent?

Great question, and one that comes up all the time. In Utah, the Code section that applies to your situation is Section 30-3-36(2). It reads as follows: 30-3-36. Special circumstances. (1) When parent-time has not taken place for an extended period of time and the child lacks an appropriate bond with the noncustodial parent, both parents shall consider the possible adverse effects upon the child and gradually reintroduce an appropriate parent-time plan for the noncustodial parent. (2) For emergency purposes, whenever the child travels with either parent, all of the following will be provided to the other parent: (a) an itinerary of travel dates; (b) destinations; (c) places where the child or traveling parent can be reached; and (d) the name and telephone number of an available third person who would be knowledgeable of the child's location. (3) Unchaperoned travel of a child under the age of five years is not recommended. As you can see, Section 30-3-36 does *not* require the other parent's consent or permission for you to travel with the child during your custodial or parent-time periods. You are required to give the other parent information pertaining to when you are traveling, where you will go, and contact information for the child, but the other parent cannot prevent you from traveling with the child by withholding "consent" because her consent is simply not required. "That's all well and good, Eric," you may say, "but if she won't let me pick up the child from her house in time to make the flight to Anaheim, my legal rights aren't any protection this weekend!" True. So if you have enough time, you can file a motion for a writ of assistance, asking the court to issue an order to your ex to exchange custody of the child with you on your custodial/parent-time day that can be enforced by local law enforcement (i.e., the police of sheriff can physically force your ex to turn over the children to you). You will generally need at least 28 days between the day you file and the day of the hearing for this work, although if you have less than 28 days between now and your Disneyland trip, you could file your motion for writ of assistance on an "ex parte" basis, and hope that the court is sympathetic to your plight and sees your situation as necessitating issuance of a writ immediately.