TMC Earth Day 5K at Biosphere 2

🌍 TMC Earth Day 5K Race Overview

Looking for a way to celebrate Earth Day? Join us at Biosphere 2 for a 5k run and walk, entirely on the grounds of the famed facility. Whether you're a seasoned athlete or just looking for a fun way to get some exercise, you're sure to enjoy yourself at the world-famous Biosphere 2.

🏞️ Event Details

• Date: April 18, 2026
• Location: 32540 S. Biosphere Road, Oracle, AZ
• Course: 3.1 mile rolling course with gorgeous desert and mountain views
• Post-race Activities: Music, food, and fun activities

🎟️ Registration Perks

• Souvenir Shirt: To first 600 registrants
• Timed 5k: Includes finisher's video
• Awards: Age group and overall awards courtesy of The Running Shop
• Tour: Free entry to the renowned Biosphere 2 tour

💰 Fundraising Purpose

The TMC Earth Day 5k is raising funds for the Ocean Reef research project, learning how to grow ocean reefs in a changing climate. See details and donate here.

📅 Race Schedule

Thursday, April 16

• 4:00 - 6:00 pm: Packet pickup and in-person registration at The Running Shop, 3055 North Campbell, Tucson
• Shirts: First 600 registered: sizing and style on a first-come, first-served basis
• Pick Up: You can pick up for others and shop at The Running Shop
• Be Prepared: Please be mindful of crowding and take pins for your racing shirt number.

Saturday, April 18

• 7:15-8:15 am: Race day registration and packet pickup in the parking lot by the front entrance
• 8:30 am: Start time for TMC Earth Day 5k Run/Walk
• 9:45 am: Free Kids Dash on the Great Lawn
• 10:00 am: Awards presentation and remaining shirts available for late registrants

👶 Family-Friendly Fun

Bring the Kids! Strollers are allowed at this child-friendly event, with a free Kid's Dash & Kid's Zone. Special $5 price for children 14-and-under includes race number, timing, and entry to Biosphere 2, but no t-shirt.

🌊 Do Good!

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

⛰️ Race Conditions

• Terrain: Mostly pavement, with a brief dirt section
• Difficulty: Hilly in sections
• Weather: Expected temperatures in the 50's - 70's
• Differently Abled: Yes, be mindful of hills and dirt road

❓ Questions & Contact

Want Training Advice? Contact RRCA-certified running coach Tia Accetta at tia@runtucson.net.

This event is a partnership between Run Tucson & the Biosphere 2, the University of Arizona.

Questions? Contact Race Director Randy Accetta at randy@runtucson.net.

🔗 More Information

For more details about the race, visit the official registration page: TMC Earth Day 5K Official Page