Principal's Office

Principal's Message

The 2023-2024 academic year is going to be another great one for all of us here at Riverdale.  It is especially exciting for me now that I am in my 2nd year.  Before starting at Riverdale, it appeared to me that I was coming to a school with amazing teachers and staff, parents who were involved in their child’s education, and students that bring awesome energy to our hallways. It turns out my assumptions were right!  Riverdale is a wonderful place for students to learn and I am proud to come into this building every single day.  I am thankful for all of the great relationships we have with the community, especially the one we share with the Riverdale Police Department.  We will continue to promote a nurturing environment where we believe all of our students can be successful academically and socially.  


There are a few different ways you can stay up to date if you are looking for information about our school. The most important is through the utilization of Remind. This is the platform we use to disseminate up to the minute information. If you are not yet using Remind, please call the Main Office and we will walk you through it. I also periodically post pictures and messages to Instagram at riverdale_principal. You should also look out for our weekly newsletters that are sent to all Riverdale parents and guardians every Friday via S'More. Take care and thank you for all you do for your children!

About the Principal
Mr. Sernatinger

Dear Riverdale,

I am thrilled to be joining the Riverdale Public School as your Principal.  I look forward to meeting each of you and learning more about you and your families.  I would like to share some of my background so you know a bit more about my history and how I arrived here to Riverdale.  I attended Franklin & Marshall College and double majored in Government and Spanish.  During my Junior year, I studied in Madrid, Spain for 5 months.  I also played football at F&M for four years.  I graduated in 1997 and worked for three years.  I then went back to school to study for my MBA and graduated in 2002.  While in graduate school, I studied in Guadalajara, Mexico for 4 months.  The experience of living in foreign countries not only helped me to become fluent in Spanish, it lit a desire in me to see the world and meet new people and understand their cultures.  

After completing my MBA, I lived in Sevilla, Spain for a few months with my brother.  I returned home to New York, and by July of 2003, I had moved to Hermosa Beach, California.  My goal was to work for an international company that needed support in Latin America.  As luck would have it, I found a job working for a dental products company called Discus Dental.  I was responsible for managing all of our business in Latin America, Spain, and Portugal.  I traveled 100 days a year for those three years and had phenomenal experiences during my travels.  As I progressed through my career as an executive, the idea of becoming a teacher was always tugging at me.  Working as an executive was not fulfilling, and I felt I needed to do something that made a difference.  I believed then (and still do) that being a teacher is one of the most fulfilling jobs there is.  I wanted to help my students learn the language that has brought so many amazing experiences and relationships to my life.  I decided to go back to school full time to learn the skills I would need to be a great educator.  I set two goals for myself when I left my career over 10 years ago: be the best Spanish teacher I could be, and then become a school leader.  To have reached this goal and join the Riverdale Public School as your Principal is the culmination of over 25 years of work and study.

I believe that every child can learn and excel in their own unique ways.  I tell my sons and will tell our students to “Do What is Right, Not What is Easy.”   As young children and adolescents, it is important to understand why we make decisions and how these decisions affect ourselves, those around us, and the future.  I have worked in middle schools and high schools as a teacher and administrator for the last 12 years.  I know what it looks like when a child enters the 9th grade with a positive and strong emotional and academic skill set.  I purposely sought an opportunity to work with elementary and middle school students because I know for a fact that these are the years that make the difference.  I will support our students, parents, teachers, support staff, and the rest of the community to ensure that when our students graduate from the 8th grade, they are prepared for high school.  We will continue to encourage our students to be hard-working, confident, resilient, empathetic, ethical, caring, and outstanding representatives of this town of Riverdale that they call home.  

The Riverdale Public School has been an outstanding place for children to learn for decades.  The reasons for this are clear: great teachers, great families, and a community that cares about their children and education.  As the new Principal, my responsibility is to continue to foster and support the educational excellence that has been established and to encourage the traditions that are a part of this school and town.  I am excited to spend time in classrooms to see our teachers in action and watch our students grasp new concepts.  I’m sure I will learn as much from them as they will from me.  I will bring all of the skills I have learned over the last 25 years as a student, as an executive, as a teacher, and as a school administrator and apply them at Riverdale.  I am confident that my creative outlook and love of the education profession will have a positive impact throughout the Riverdale Public School and all those that care about it.  I look forward to becoming a part of the Riverdale community and meeting as many of you as possible.  Thank you for this opportunity and I look forward to seeing you.

Best Regards,

Mark Sernatinger

[email protected]

instagram: riverdale_principal


Mr. Sernatinger's Graduation Speech for the Class of 2023


For many of you, your journey at Riverdale began here in PreK or Kindergarten.  It’s incredible to think that this is your last day. 

All of the grownups here can tell you that this coming era in your educational journey will be full of excitement.  You will have opportunities to make new friends, to join clubs, play different sports, be a part of the performing arts and music, and challenge yourself in different ways academically.  

Most importantly, you will have countless opportunities to fail.  I’m not talking about failing classes, I’m talking about those moments when you give your best, but you still come up a little short.  Embrace these moments. My football coach in college, Tom Gilburg, used to tell us, “little things make big things.”  So when you realize you have a weakness, find little ways to improve… bit by bit the little things you do will become big successes in the areas you once feared.    

You are all old enough to understand that you cannot control everything that occurs around you.  What’s important… is that you can control how you react.  Each of you is so young and so strong.  Don’t let someone else push you off of your path.  Decide that you can… and you will.  When you are nervous before a test, a game, a performance, a tough conversation… embrace that feeling and that tension.  At your age, every situation is a learning experience.  Prepare as best you can and give it 100%.

Most importantly… have fun… Work hard… and Play hard!  Of course it’s important to put in the time and preparation for academics, but give yourself time to enjoy an activity that isn’t school related.  Be with your friends and have fun.  When we were at our overnight, I saw a group of kids that love to laugh.  I also noticed that each of you are leaders in your own way.  You can be a leader just by projecting a positive attitude and showing others that you care about them.  People will follow your example.  

Even though not everyone is headed to Pompton in September, no one can ever take away the foundation you have all built here together.  

I hope you will hang out with your friends over the summer and talk about the great memories you created together at Riverdale School.  I guarantee the next four years of high school will provide you with experiences you will never forget.  Just remember, you can always come home to Riverdale School.  I can’t wait to see what each of you will accomplish over the next four years… and beyond.  We love you and we know the world is a better place because each of you is in it.  Thank you for what you have given to Riverdale School… and Congratulations Class of 2023 :) 

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