@Brandon Carlson, leases commonly give landlord the right to enter/inspect the property with notice (often 24 hours) or in an emergency with no notice.
Of course the tenant isn't thrilled about it, but why would they think they could or should refuse? Even if they had the right to refuse, they would likely be non-renewed at the end of their agreement and be looking for a new place to live.
Landlord needs to give notice, not ask for permission. Unless all the landlord wants to do is go hang out on their couch and watch their TV. A legitimate reason is needed. A walkthrough inspection is one of them.
In California, you must indeed give 24 hour notice to inspect a property. That includes the grounds and any property / parcel space that is covered in the lease. If the land (or a portion thereof) is not included in the leasehold agreement, you would not need to give notice - but it would certainly be a kind courtesy and encourage positive sentiment from the tenant(s)!
I would also add that notice should be given in WRITING so that any questions related to the conduct can be documented. CYA!!!!
Laws vary, but they all agree on one thing: the Landlord has a right to enter the property for inspections, maintenance, showings, etc. In the State of Wyoming (it really does exist), the law says we have to give "reasonable" notice. Other states require a specific amount of time, like 24 hours, and they may dictate that entrance be during specific hours of the day or days of the week. There are always exceptions for emergencies.