Fathers of young children were historically at a disadvantage in seeking custody of their children due to tender years doctrine—a theory courts adopted in the belief that children had a greater need for the love and care of their mothers during their tender years. Under the tender years doctrine, custody of young children was automatically given to the mother unless there were unusual circumstances. Today, courts more often recognize the important role both parents play in the lives of young children, and usually order some form of shared custody arrangement. But there are factors the court may consider that sometimes favor one parent over the other in determining who will be the primary custodian of the children—such as giving preference to a parent who has not been working outside the home, and has therefore been spending more time taking care of the children’s daily needs.

In Montana, the tender years doctrine, which historically favored mothers in child custody cases, is no longer a legal standard. Instead, Montana courts follow the 'best interests of the child' standard, as outlined in Montana Code Annotated § 40-4-212. This standard requires courts to consider various factors to determine what custody arrangement would be most beneficial for the child, without an automatic preference for either parent based on gender. Factors considered include the wishes of the parents and the child, the child's relationship with each parent, the child's adjustment to home, school, and community, and the mental and physical health of all individuals involved. Montana courts encourage joint custody arrangements when it is in the best interests of the child, and both parents are considered to have equal rights and responsibilities towards their children. The primary focus is on ensuring that the child maintains frequent and continuing contact with both parents, and the courts will consider which parent has been the primary caretaker, among other factors, when determining custody arrangements.