50 Dean Lane, Stony Brook NY 11790
Phone: (631) 730-4300  |  Fax: (631) 730-4309

Attendance/Health Office: 730-4310
Transportation Office: 730-5070, Fax: 730-5095
Weather Related Closing Information: 730-4050

Kathryn White, Principal
Merrilleen Heidrich, Assistant Principal

School Hours: 9:25 a.m.-3:40 p.m.

School Drop-Off/Pick-Up Procedure

Building Security Information



 Photo Gallery



Click Here for A Letter from Our STEM Teachers! - New

October is Fire Prevention Month


 On October 16th the Stony Brook Fire Department visited Mount Elementary School to teach the children about Fire Safety.  Thank you to all the Stony Brook Fire Department Volunteers for coming and spending time with the students!  The children enjoyed learning about the importance of fire prevention!


Hip Pickles Come to Mount to kick off the 2015 - 2016 School Year! 

Thank you to the Mount PTA for this fun event that taught students about treating others the way they would like to be treated in a fun and interactive way!




Article: Keeping Kids Cool at School 


2015-2016 Supply Lists 

(Now located on side navigation)





William Sidney Mount School is one of five elementary schools located in the Three Village School District in Stony Brook, NY.  Currently, we house grades kindergarten through sixth grade.


US Dept. of Education designates WS Mount as a Blue Ribbon School!!
Click here for more information.  Visit the Dept of Education website.
Click here to watch the video!

Please be sure to check the Calendar and the Parent Notices regularly for important updates throughout the school year.   



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Saturday, November 28, 2015   |  District Home