Complex sentence: Transmountain Early College High School, commonly referred to as TMECHS, is an EPISD Early College High School and STEM School which allows students to take courses at the El Paso Community College Transmountain Campus and receive an Associate's Degree by the time they graduate high school.
Split into simpler sentences: Transmountain Early College High School, commonly referred to as TMECHS, is the Early College High School for the EPISD school district. TMECHS participates in the STEM School program, which allows students to take courses at the El Paso Community College Transmountain Campus and receive an Associate's Degree by the time they graduate high school.