97 Geo Tracker 4x4 Auto trans flat tow: Tranny in park? Why?

OK thanks for the explanations and suggestions! WyoTraveller and D.E.Bishop called it right, transfer case was not in neutral, it was in 4H best I can tell. I made the mistake of assuming it it wiggled side to side that was neutral. Nope! I can;t read the letters on the actual shift knob so I consulted the manual and figured out I needed to have the knob another notch forward to be in neutral.
Thanks again, will give it another tow try tomorrow.
Jack