One who sells real property has a special or vendor's lien thereon, independent of possession, for so much of the price as remains unpaid and unsecured otherwise than by the personal obligation of the buyer.
35-20-02. Vendor's lien waived by transfer of written contract for payment - Exception. When a buyer of real property gives to the seller a written contract for payment of all or part of the price, an absolute transfer of the contract by the seller waives the seller's lien to the extent of the sum payable under the contract, but a transfer of the contract in trust to pay debts and return the surplus is not a waiver of the lien.