I'm not sure how that could pass on to a new owner. I'd call the Cass County treasurer's office. Here is what the gov reg says..
REG-40-002 GENERAL RULES APPLICABLE TO PROPERTY TAX EXEMPTIONS
002.01 All property in the State is subject to property tax unless an exemption is mandated or permitted by the Nebraska Constitution and enabling legislation is adopted by the Legislature. Federal law may supersede the Nebraska Constitution with regard to taxation of property owned by the federal government or its agencies or instrumentalities.
002.02 Property tax exemptions are to be strictly construed and the burden of proof is on the party seeking an exemption to show that the property is eligible for exemption. Property tax exemptions may be allowed based on the inherent nature of the property, the ownership of the property, the use of the property, or a combination of these factors.
002.03 The following property is exempt from property taxes:
002.03A Property owned by the state and its governmental subdivisions that is used or being developed for use for a public purpose. See Chapter 15, Property Owned by the State and Governmental Subdivisions Regulations;
002.03B Property owned by and used exclusively for agricultural and horticultural societies;
002.03C Property owned by educational, religious, charitable, or cemetery organizations or any organization created for the exclusive benefit of any qualified organization, and used exclusively for educational, religious, charitable, or cemetery purposes. The property cannot be (1) owned or used for financial gain or profit to either the owner or user, (2) used for the sale of alcoholic liquors for more than 20 hours per week, or (3) owned or used by an organization which discriminates in membership or employment based on race, color, or national origin;
002.03D Household goods and personal effects not owned or used for financial gain or profit to either the owner or user;
002.03E The increased value of land by reason of shade and ornamental trees planted along the highway;
002.03F Non-depreciable tangible personal property;
002.03G Motor vehicles required to be registered for operation on the highways of this state;
002.03H Business and agricultural inventory which includes personal property owned for purposes of leasing or renting the property to others for financial gain only if the personal property (1) is leased or rented 30 days or less, in the ordinary course of business, (2) may be returned at the option of the lessee or renter at any time, and (3) is considered household goods or personal effects if owned by an individual;
002.03I Certain depreciable tangible personal property for a specified period of time when a taxpayer has signed an agreement pursuant to the Employment and Investment Growth Act or the Nebraska Advantage Act;
002.03J Livestock, which includes all animals or other living creatures used or raised for profit;
002.03K Depreciable tangible personal property used directly in the generation of electricity using wind as the fuel source, such as in certain wind energy generation facilities that are commissioned or in commercial operation; and
002.03L Personal property that is assembled, engineered, or processed as part of a data center, for the purpose of subsequent use at a physical location outside this state. Data center means computers, supporting equipment, and other organized assembly of hardware or software that are designed to centralize the storage, management, or dissemination of data and information.