TMMS Activities Registration 

To sign up for TMMS Activities, please follow these steps to finalize your registration and ensure your student is cleared for participation. 

1.Create an Arbiter Registration Account (you only need one for your whole family.)

-You can create your account by clicking here. Only use this link once.

2.Activate your Arbiter Registration account, from the activation link that will be automatically sent to your email. (Note: this email may go into your junk folder.)

-If you are having trouble creating your account, receiving the activation email, or logging in, you can contact support at

registration@arbitersports.com or call Arbiter at 800-311-4060.

3.Once you have successfully created your account and are logged in, please click on the link below to complete your student’s registration: https://students.arbitersports.com/organizations/thunder-mountain-middle-school

-you can access the registration guide by clicking here.

-you can access the video registration guide by clicking here.

4.After completing your registration, you will receive an email notification confirming that we have received your submission. Students MUST be registered and cleared in Arbiter to be eligible for participation in TMMS activities.