Cayler Prairie State Preserve is a 160-acre land parcel of tallgrass prairie located in the northwest region of the U.S. state of Iowa in Dickinson County near Spirit Lake.

Prairie forbs include (in spring) golden alexander and Lambert's crazyweed; (in summer) sawtooth sunflower and prairie rose; and (in fall) Missouri goldenrod, New England aster and dotted gayfeather.

[2] Historically, much of the visitation to the prairie has been connected with wetland and upland wildfowl hunting.

The prairie was uncovered by botanist Ada Hayden in 1944, who recognized tallgrass plants growing in a hayfield.

She recommended that it be preserved as one of the last remaining patches of old-growth tallgrass prairie in Iowa.