Sherman County's Assessor's Office is responsible for valuing all real and personal property for property tax purposes. Annually, this office determines the property's real market value and calculates its maximum assessed value. Property owners are taxed on the lesser of the two, which is referred to as the assessed value.

The Assessor role is an elected office, answerable to a public vote every four years. The Appraiser is a staff position.

Thanks to the Assessor's Office, Sherman County is able to use property taxes to fund local taxing districts and County agencies. The Assessor's Office also is responsible for accurately posting all recorded documents, processing mapping changes, managing County GIS data, and maintaining records pertaining to property ownership, manufactured structures, commercial personal property, and the County's property-tax exemption program.