It could be:
* Under the truck bed: This is the most common location. You'll likely need to remove a panel or access cover in the bed to reach it.
* Under the rear seat (if applicable): Some extended cabs might have space for a spare under the rear seat.
To find it, I recommend:
1. Check your owner's manual: This is the best source of information.
2. Look under the truck bed: Carefully examine the bed for access panels or covers.
3. Check under the rear seat (if applicable): If you have an extended cab, lift up the rear seat cushions to see if there's a spare tire there.
If you can't find it after checking these locations, a visual inspection of the underside of your S-10 might be necessary, or consult a mechanic or a Chevy dealership.