Hopefully the name will be evident upon arrival at ground zero. You are looking for a magnetic hide-a-key with a log and pencil.
Though I've not personally visited this museum, it holds a special place in my heart. My father-in-law was born in the white house (former Osceola hospital) and our own three sons were born at the adjacent Annie Jeffrey Hospital...the sweetest picture of the rare rural hospital. In fact, when our oldest was born on a hot July day, his daddy took him outside to show him the tall cornstalks within "touchable" distance!! THIS is an image of Nebraska at its best.