Wizard Island was created after Mount Mazama, a large complex volcano, erupted violently approximately 7,700 years ago, forming its caldera which now contains Crater Lake.

Its surface features and lack of a crater indicate that Merriam Cone formed under water.

Current public access to Wizard Island is available only during the summer months when boat tours on Crater Lake are in operation.

[7] Passengers on boat trips early in the day may choose to disembark on the island, but must be prepared to spend the entire day on the island if subsequent boats are too full to take on additional passengers.

A final boat is dispatched at the end of each day to pick up any stragglers since overnight camping is not permitted on the island.