District boundaries have changed over time, therefore, senators before 2021 may not represent the same constituency as today. From 1993 until 2003, the district covered eastern Washington County; from 2003 until 2013, it shifted to cover southern and eastern Lane County, including much of downtown Eugene, as well as northern Douglas County; and from 2013 until 2023, it stayed mostly the same while gaining some of southern Creswell and northern Roseburg.
The current district is substantially different from its previous iterations. It is substantially physically smaller and is centered around the downtowns of Eugene and Springfield while not containing any other incorporated cities.
^{{cite web |title=Corcoran to leave Senate for job on state panel |url=https://nwlaborpress.org/2003/10-17-03SEIU.html |website=NW Labor Press |publisher=NW Labor Press |access-date=14 January 2024