HARVARD, Ill. (AP) _ Mary Esther Elizabeth Blodgett, the first woman in Illinois to own and operate a commercial radio station, died Monday. She was 85.

Ms. Blodgett, who ran station WMCW-AM in this northern Illinois town from 1955 to her retirement in 1979, died at a nursing home in nearby Woodstock, said station owner Mianne Mitchell Nelson.

During the years she owned the station, Ms. Blodgett sold advertising, produced live musical broadcasts and wrote and delivered her own newscasts.

''In all those years, she missed only one day on the air, and that was the day they buried her father,'' Mrs. Nelson said. ''She was certainly the first woman owner-operator in Illinois, and we belive she may have been the first in the nation.''

Ms. Blodgett, born in Lake Geneva, Wis., began her broadcast career with radio station WBEL-AM in Beloit and came to Harvard as McHenry County correspondent for that station.

''After a few years, she decided she wanted a radio station of her own, so she applied to the Federal Communications Commission for a license,'' Mrs. Nelson said. ''She never married and was quite proud of that fact, so she signed her correspondence with the FCC 'Esther Blodgett, Spinster.'''

Ms. Blodgett was granted a license in 1954, the first issued for a station in McHenry County, and the station began broadcasting Jan. 30, 1955.

''She played everything from Montovani to polkas, and she kept a piano in the studio for local people who wanted to come in on Sunday afternoons to play over the air,'' Mrs. Nelson said. ''Some Sundays, she would hire a polka band and have them play on her front porch. She had her microphones set up there, so people could come with picnic lunches and hear the program live.''

On her retirement, Ms. Blodgett sold the station to Obed Borgen of Preston, Minn., who resold it three years later to its current licence holder, Mitchell Broadcasting Co., of Grinnell, Iowa.

Ms. Blodgett is survived by a nephew and a niece.