I belong to AIS and TBIS. There is an Iris Club right here in Kentucky (Bluegrass Iris Society), as Jane has already described -- but it is centered in Lexington, which is the north central part of the state. I live in the far western part of the state, five driving hours away -- which makes it impossible to participate.
But I enjoy the magazines from the two organizations I do belong to, and the activities that I can participate in -- such as the photo contest at AIS, etc.