Montana is now the first state to specifically ban people dressed in drag from reading books to children at public schools and libraries.
The law took effect immediately after Republican Gov. Greg Gianforte signed the bill on Monday.
Bills in Florida and Tennessee also appear to try to ban these events, but both states' measures apply to performances that are sexual in nature.
Montana's law — while it defines such an event as one hosted by a drag king or queen who reads children's books to minors — does not require the event to include a sexual element to be banned.