Boldt Castle Hours and Season

Boldt Castle is a seasonal attraction and closes entirely outside its season — there is no winter opening.

The 2026 season

• May 9 to October 12
• Daily 10:30 am – 6:30 pm
• Independence Day weekend: open until 7:30 pm on Friday July 3rd and Saturday July 4th

Three closing times, not one

The castle’s advertised 6:30 pm is the last of three deadlines, and it is the least useful one to plan against.

If you are arriving from the Canadian side, the binding constraint is the port of entry at 5:30 pm — you cannot clear into the United States after it shuts, no matter that the castle is still open for another hour. See the border crossing.

If you are arriving from Alexandria Bay, the binding constraint is the admissions booth, which also closes an hour before the castle. Turning up at 6:00 pm means a very short visit at best.

How long to allow

Most visitors spend two to three hours on Heart Island for the castle, grounds, Alster Tower and Power House. Adding the Yacht House across the water pushes that towards four, since you need the free inter-island shuttle in both directions. Working back from the 5:30 pm booth closing, the practical latest sensible arrival is early afternoon.

Shoulder season

May and early October are the quietest and the shuttle queue is short, which matters because shuttle tickets cannot be pre-booked. The trade-off is weather on an exposed island in the middle of a wide river.