TMC Earth Day 5k at the Biosphere 2
Saturday, April 23rd
Capped at 400
Join us in cruising the hidden backroads of world-famous Biosphere 2, nestled at the base of the majestic Catalina Mountains, north of Tucson. The rolling 3.1 mile course offers gorgeous desert and mountain views, with start and finish on the Biosphere 2 Lawn. All participants receive free entry into the Biosphere 2!

Don't miss this chance to visit the earth's entire ecosystem under one roof while celebrating Earth Day.

To ensure a unique experience, the race is capped at 400 registrants -- all registrants receive these cool swag items:
  • souvenir race shirt -- technical shirt in both "women's cut" and "unisex" styling
  • commemorative race medal - design announced soon!
  • official finisher's time with chip timing
  • free entry to the world-famous Biosphere 2
  • discounted entry to spectators, plus free entry for children
  • post-race snacks and goodies
  • age-group and overall awards announced soon
Souvenir lightweight technical shirt produced in the US by Leslie Jordan Designs in Oregon
V-neck Cut
Saturday, April 23rd Planned Schedule:
7:30-8:15 Race day registration and packet pick up
8:30 Start time for TMC Earth Day 5k Run/Walk
9:45 Free Kids Dash
10:15 Awards 

Ongoing: All registrants can visit Biosphere2 on their own -- no need for a formal tour!

All non-running guests can purchase Biosphere 2 admission for the discounted rate of $11 (before 8:30 am) and all children under 12 are free.

Bring the Kids! Strollers are allowed at this child-friendly event, with a free Kid's Dash & Kid's Zone. Children 12 and under are free between the hours of 6am and 10am.

Do Good! This inaugural event raises funds for the world-renowned Biosphere 2's Ocean Reef Lab. 

Terrain: mostly pavement, with a brief dirt section ... and, well, it's hilly in some sections...

Weather: 50's - 70's

Discounted Visitor Pricing: All runners receive free entry to the Biosphere 2, while all all Earth Run spectators 13 years and older receive the reduced general admission fee of only $10 per person. Children 12 and under are free between the hours of 6am and 10am. Your admission not only gets you access to the grounds but is also good for the Biosphere 2 Experience. 

The Biosphere 2 Experience app helps guides you around and through Biosphere 2 and includes never before seen photos and videos that visualize the science and 30-year history. Through science stories and interviews you'll have the opportunity to learn more about our amazing, world-class research as you traverse a safe (socially distanced) one-way path around the exterior and through the human habitat and wilderness areas of Biosphere 2. Your admission fee helps to support Biosphere 2’s education and research initiatives.

Accessibility: While the race course is accessible to all, please be mindful of hills and varied terrain. Much of the Biosphere 2 campus is wheelchair accessible, though certain areas of the property are not accessible due the steep terrain and the presence of stairs. The majority of the biomes, including the desert, savanna, ocean and rain forest, are all accessible by wheelchair or scooter.

Pets and Service Animals: While pets are not allowed inside Biosphere 2 or on the grounds, service animals that are trained to do a specific task are welcome. Please do not leave pets unattended in vehicles.

Want Training Advice? Contact RRCA-certified running coach Tia Accetta at 

This event is a partnership between Run Tucson and the University of Arizona's Biosphere 2.
We are beyond grateful to Tucson Medical Center for joining as the title sponsor for this unique event. Check out TMC locations throughout Southern Arizona, including a TMC One office on La Canada and Lambert for those in the Oro Valley/Catalina area. See for a location near you.
Gabe Z Triple Crown
Race Series
This is a 3 race series starting with the TMC Meet Me Downtown 5K on June 5, the TMC Tucson 10K/5K in September, and the TMC Get Moving Tucson Half Marathon/5K in October. The Gabe Zimmerman Triple Crown raises funds for the BEYOND-Tucson Foundation.
TMC Meet Me Downtown 5K
June 4, 2022
The TMC Meet Me Downtown Night Run and Festival of Miles is fun way to kick off hot summer running in Tucson! The downtown vibe comes alive especially when combined with running endorphins, bands, a beer garden, and, we hope, free ice cream!
Run Tucson is a proud member of the Oro Valley Chamber of Commerce
For information about our events, the RRCA, and The Workout Group, contact Randy Accetta
(520) 991-0733
For information about in-person, online, or group coaching, contact contact Tia Accetta.