When is a unit abandoned?

[Ariel K.]

I own an RV park in TX.  It's a long-term living RV park where the tenants own their own RV.  The manager tried to get in contact with this tenant and after 3 weeks, the tenant claimed she was in the hospital.  The tenant hasn't been to her RV since and we have confirmed from some of the tenant's associates that the story was a lie and they haven't seen her.  When is property considered abandoned?  When are we allowed to dispose of her belongings?  Is an eviction required? Thanks in advance!