2015-12-20 drinking; drinking age; laws; idaho; washington; alcohol; uidaho; university of idaho; history; history of drinking In 1983, students and businessmen alike let out a sigh of relief when a bill to raise Idaho’s drinking age from 19 to 20 failed. The drinking age was raised to 21 in 1987. From the 1983 Gem of the Mountains Digital Yearbook.