I would seriously doubt that an inspector can just walk onto your property.
I know here in St Petersburg, FL they cannot. If you fence your property they are not even allowed to touch your fence. They can look over etc. but they are not allowed to simply walk onto your property.
Unless it is a migrant labor camp, then the health inspector has the right to enter (F.S. 381.0088) and the Sheriff has the duty to fully assist (F.S. 381.0012(5)). They do have the right to apply for a warrant under Chapter 381. I’d assume Indiana has something similar.