How far in advance can we reserve the picnic shelters?

Hello! The window for reserving shelters is 12 months in advance. Reservations can be made up to 4 days prior to arrival during peak season (May 1 to September 30) and 7 days prior to arrival during the off season (October 1 – April 30). More info here: https://www.iowadnr.gov/Places-to-Go/State-Parks/Make-a-Reservation

Call the dnr

Have booked up to a year in advance

At least 30 days that I know of

Have to do it through the don't, so they would be able to tell you.