Mark Sims graduated from L.V. Berkner High School in Richardson, Texas, in 1980. He earned an Associate’s Degree from Richland Jr. College in Dallas, Texas, in 1982, followed by a Bachelor’s Degree from North Texas State University in 1984. In 2001, he completed a Master’s Degree in Educational Leadership from Stephen F. Austin State University.

With over 40 years of experience in education, Mr. Sims began his career in the Galena Park School District in 1985. After obtaining his Master’s Degree, he joined the Channelview Independent School District (ISD) in 2001, starting as an assistant principal at Channelview High School. In April 2005, he was appointed to lead the Endeavor program.

Mr. Sims believes that Endeavor not only provides students with the opportunity to earn their high school diplomas but also positively impacts the lives of students, parents, and staff in the Channelview community. He asserts, "If we Focus Our Commitment to Unlimited Success (FOCUS), our students will thrive in any endeavor they choose. I want the students at Endeavor High School to believe in themselves, recognize the importance of education, and become productive members of the Channelview area."

Mr. Sims has been married to his wife, Marsha, for over 40 years, and they have two sons, Clay and Reid. Additionally, he has been actively involved in various local church music ministries and cover bands for over 45 years. He enjoys playing in bands with his son, Reid (guitarist).