Proceeds help pay for equipment and tournament fees for more than 50 athletics programs at M-A, said spokeswoman Diana Holliday.
Entry fees are $25 for adults and $15 for students 18 or younger. Rates jump slightly after April 29, and for online registration. Same-day registration begins at 7:30 a.m. at the main gym.
Go to www.active.com to register online. Set the search locality for "Atherton" and enter "big bear run" in the search box.