Inland Empire Regional Tournament

Division B and C teams from the Riverside and San Bernardino Counties compete for the opportunity to advance to the Southern California State Tournament in April.

Location: Etiwanda High School, Rancho Cucamonga
Date: March 11th, 2023
Divisions: A, B, C
Regional Director: Colleen Duncan

October Update

Coaches’ Meeting

Our Annual Coaches’ Meeting will be held virtually this year on December 3, from 10am-12pm. The first portion of the meeting will be focused on the Tournament: registration, necessary forms, rules for the day, etc. The second portion will be geared more towards newer coaches and be open for questions and clarifications.


If you have registered your team(s), you have been sent information about obtaining your Certificate of Insurance. Information on this can be found at the bottom of this webpage.


Registration is open at There is no limit to the number of teams you can register. Payment for your teams must be received by February 25, 2023 in order to participate on the day of the event. Refunds will not be issued after December 16, 2022. Team numbers will be issued after that date.


IERSO will be using the same event schedule as the State Tournament. The preliminary schedules for all Divisions can be found at the bottom of this page. This year’s event rules have been posted on for Divisions B and C. Division A information will be available once finalized.

Contacting Us

Please send your questions to us at, or click on ‘Colleen Duncan’ at the top of this webpage. We will send out more information as it becomes available. If you would like to be removed from our mailing list, please let us know.

Welcome to the 2022-2023 Season!

Team Registration is now open for the 2022-2023 season! Click here to register. The 2022-2023 Preliminary Regional Schedule is posted here and the rules are available online for free on the National Science Olympiad web page.

Number of Teams per School

The limit on the number of teams per school has been removed. All teams are expected to compete at the Regional Tournament.

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