Paul D. Mills, 90, a former Gaithersburg dairy farmer who in the mid-1940s helped sow the seed for the popular Montgomery County Agricultural Fair, held every August for the last 50 years, died of congestive heart failure Sept. 24 at Shady Grove Adventist Hospital in Rockville.

Mr. Mills was one of about a dozen Montgomery County farmers and agriculture officials who revived the idea of an annual county fair to show off livestock, farm machinery and home-cooked country food. The idea led to the construction of the Montgomery County Agriculture Center on a 65-acre fairground in Gaithersburg in 1949.

From that time to last August, Mr. Mills participated in county fairs as an organizer and exhibitor. During the fair's early years, he oversaw rental of commercial spaces to politicians, car dealerships and farm equipment company representatives.

In later years, he displayed antique milk bottles and other items in the Old Timers Show and home-grown fruits and vegetables in the Farm and Garden Department.

He also served on the agriculture center's finance committee from 1948 to 1951 and was chairman of the logging committee from 1947 to 1957. He served on the center's board of directors for 12 years and was its vice president in the mid-1950s.

A Gaithersburg native, he attended Travilah School, a one-room schoolhouse in Potomac, and the old Rockville High School. As a young man, he was a saxophonist in a band.

From 1931 to 1945, he owned and operated the 198-acre Pleasant Meadows Dairy Farm in Gaithersburg. He sold his herd and began commercial farming -- growing corn, raising hay and plowing gardens. His largest contract was grading, seeding and planting trees for what is now the National Institutes of Standards and Technology when it built its campus in Gaithersburg in the mid-1960s.

He retired in 1982, sold all but two acres to a developer and sold produce from a small stand in his front yard. He also dispensed historical information about the area to anyone who cared to talk and, when not manning the stand, left a sign on the table that read: "Honor system. Leave the money in the box."

His wife, Catherine Johnson Mills, died in 1981.

Survivors include a daughter, Carol Mills Weiger of Gaithersburg; a stepdaughter, Betty Grabis of Gaithersburg; a sister, Dorothy Kilby of Gaithersburg; five grandchildren; and seven great-grandchildren.