Start your research by finding the property's legal description and the building's construction date. Look at the property tax statement or the Tulsa County Assessor's website for a property's legal description and a building's date of construction. The legal description is found in the quick facts and general information sections. A legal description shows the exact location of a property and includes township, range, and section. The date of construction is found in the improvements section. Note that the date of construction on the Assessor's website is a good place to start but is not always accurate.