Thomas attended the local Medicine Lodge school through the 11th grade, the last grade the school offered. He moved to Pasadena, California and finished high school at John Muir High School. He attended Pasadena Junior College for two years and then obtained a Bachelor of Science degree in Forestry in February, 1941, from the University of Idaho, at Moscow, Idaho.

In 1950, he enrolled in Texas A&M University, at College Station, Texas, where he obtained a MS degree in Wildlife Management in 1951 and a Ph.D in Wildlife Management in 1954 (called Range Management then).
From the passage provided, extract where Thomas finished high school.
Thomas finished high school at John Muir High School in Pasadena, California.