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School Open
Dismissal: 3:30 PM
Next 7 Days
August 2026
Coming Up
School Breaks
Holidays (No School)
The School District Not Defined school calendar for the 2026-27 school year runs from Monday, August 17, 2026 to Thursday, May 27, 2027 in Mammoth, Wyoming.
- •2 scheduled breaks and 13 holidays throughout the year
- •Spring break: Mar 29 – Apr 2
- •Winter break: Dec 21 – Jan 1
School District Not Defined starts school 366 days later than most Wyoming districts. Winter break starts 364 days later than the most common Wyoming schedule.
Download the iCal file above to sync all School District Not Defined dates with your phone or computer.
Frequently Asked Questions
Is School District Not Defined school open today?
Yes, School District Not Defined is open today. Check the weekly calendar above for upcoming school days and closures.
When is the next day off for School District Not Defined?
The next day off is Monday, September 7, 2026 for Labor Day.
When is the first day of school for School District Not Defined?
The first day of school for School District Not Defined in 2026-27 is Monday, August 17, 2026.
When is the last day of school for School District Not Defined?
The last day of school for School District Not Defined in 2026-27 is Thursday, May 27, 2027.
When is spring break for School District Not Defined?
Spring break for School District Not Defined is Monday, March 29, 2027 to Friday, April 2, 2027.
When is winter break for School District Not Defined?
Winter break for School District Not Defined is Monday, December 21, 2026 to Friday, January 1, 2027.
When do students go back to school after winter break?
Students in School District Not Defined return to school after winter break on Monday, January 4, 2027. Winter break ends on Friday, January 1, 2027.
When is Thanksgiving break for School District Not Defined?
Thanksgiving break dates for School District Not Defined are not yet available.
How do I add School District Not Defined calendar to my phone?
Click the "Add to Calendar" button at the top of this page to download the iCal (.ics) file. Then:
iPhone/iPad: Tap the downloaded file, then tap "Add All" to add events to your Calendar app.
Android: Open the file with Google Calendar, review the events, and tap "Import".
Google Calendar (web): Go to Settings → Import & Export → Select the .ics file → Import.
Outlook: Double-click the file or drag it into your Outlook calendar.
Apple Calendar (Mac): Double-click the file or go to File → Import → select the .ics file.
What school district is Mammoth, WY in?
Mammoth, Wyoming is served by School District Not Defined. This page shows the 2026-27 school calendar including first day, last day, breaks, and holidays.
When does school start in Mammoth?
School in Mammoth (School District Not Defined) starts on Monday, August 17, 2026 for the 2026-27 school year.
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Last updated: July 13, 2026