Once upon a time, I was a little girl growing up in Madera. In what the kids call the olden days, Madera had a handful of elementary schools, one junior high and one high school.
According to Wikipedia, the high school founded in 1894 is the first and original San Joaquin Valley high school. A cursory search of the Internet didn’t find the date they adopted the Coyote mascot.
My mother, QuoVada, graduated from Madera Union High School in 1949. The Coyote was on the job then.