Administrative Staff

Mr. P. Grossweiler
Mr. Philip Grossweiler
Head of School/Principal
Ms. Olga Snelling
Assistant Principal
Ms. Corina Saenz
Assistant Principal
Joseph J. Kingston
Testing Coordinator
Mrs. R. Nava
Mrs. Rocio Nava
IB Coordinator
Principal's Message
Welcome to our Alonzo De Leon Middle School school website! 
We're proud and honored to have the opportunity to educate your children.
Your satisfaction is important to us, so let us know how we're doing.
I wish all of you a very safe and successful school year!
About Ms. Snelling
Education is my passion.  The passion has been to create an environment for meaningful learning that fosters students to become life-long learners focused on making dreams come true.  I have had the pleasure of teaching only prime number grades, but have been an administrator in elementary, middle school and high school levels.  I join the DeLeon Lion Pride to effectively utilize the learning community to improve and impower teacher and student learning as we continue to grow in our academic and emotional intelligence.
About Ms. Saenz


Corina Saenz began her career in education as a teacher in 2004.  With seven years experience in the classroom teacher she pursued to advance her education and position and in the summer of 2013 she became an administrator with McAllen ISD.  She is currently the Assistant Principal for 6th and 8th grade.

Mrs. Saenz holds a Bachelor’s degree in Kinesiology from the University of Pan American and a Master’s in administration leadership from Grand Canyon University.  She holds certification for Principal in Arizona and Texas.

About Mr. Kingston
About Ms. Nava
My name is Rocio Nava and I have been in education for 12 years.  I taught middle school math and Algebra 1 for 8 years. 
I was an instructional coach for 4 years at De Leon MS and 1 year at McAllen ISD.  I am proud to be a member of our McAllen ISD family.  I have a promise with our community to provide the best educational experience for all our students.