TMC Earth Day 5k at the Biosphere 2, April 22, 2023

April 23 Update:
Check out the race report here, with information on awards, photos, results, and more from the TMC Earth Day 5k at the Biosphere 2. Award winners can pick up Running Shop Gift Cards at The Running Shop, 3055 North Campbell in mid-town Tucson. If you have not received your shirt or medal, remaining items can be picked up at The Running Shop through May 15.
See www.roadrunnerracetiming.com for all results.
April 8: Check out the Morning Blend interview about the race.
Run the Desert . . . then roam through a rain forest, view an ocean reef, and wander through savanna grass lands . . . all in one day!
Join us on Earth Day in 2023 for the TMC Earth Day 5k, where you can walk or run the hidden backroads of the world-famous Biosphere 2, nestled at the base of the majestic Catalina Mountains, north of Tucson.
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.
Limited to 500 Registrants — what you get:
- Souvenir race shirt in soft cotton feel
- Commemorative race medal, made with recycled materials
- 15% discount to Oracle’s spectacular ARIZONA ZIPLINE ADVENTURES.
- Staycation prices at iconic Westward Look Resort
- Free entry to the world-famous Biosphere 2
- Snacks and drinks
- Food trucks
- COX Conserves special festivities planned
The rolling 3.1 mile course offers gorgeous desert and mountain views, with start and finish on the Biosphere 2 Lawn. Don’t miss this chance to visit the earth’s entire ecosystem under one roof while celebrating Earth Day.
Visit our RunSignUp registration page for registration information and all event details.
Click here for the video our wonderful race photographer Damion Alexander put together.
Click here to see the KGUN Morning Blend pre-race interview about the event.
7:15-8:15 am: Race day registration and packet pick up at front entrance to Biosphere 2
8:30: Start time for TMC Earth Day 5k Run/Walk
9:30: Free Kids Dash
9:45 or so: Awards, courtesy of the Running Shop. Remaining medals and shirts given to late participants
10:00 Event wrap-up
Distance: 5k Run and 5k Walk
Bring the Kids! Strollers are allowed at this child-friendly event, with a free Kid’s Dash & Kid’s Zone
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
Difficulty: hilly in sections
Runner Quote: Amazing course. Great setting and wonderful cause. Thanks again.
Weather: 50’s – 70’s
Chair Athletes: Chair athletes may find this a doable but challenging course, with a couple of steep hills and the dirt road.
Pets Allowed: No, pets are not allowed on the Biosphere 2 grounds.
Want Training Advice? Contact RRCA-certified running coach Tia Accetta at tia@runtucson.net.

Click here for the Run Tucson race report.
Click here for the race results from our good friends at Roadrunner Race Timing.
The TMC Earth Day 5k is a 30 minute drive from Tucson and a bit more than an hour from Phoenix.
Directions to Biosphere 2 From Central Tucson
From central Tucson, go north to River Road and turn left (heading west)
Continue on River Road and turn right on Oracle Road/AZ Highway 77
Drive north approximately 24 miles on Oracle Road/AZ Highway 77
Turn right on to Biosphere 2 Road at Mile Post 96.5
From Phoenix Sky Harbor International Airport
After leaving the airport, follow the signs to I-10 E
Take I-10 E toward Tucson, to Exit 185 and exit the interstate
Turn left onto Highway 387 and continue past Coolidge until Highway 387 intersects with AZ Highway 79 near Florence
Turn right on to Highway 79 and follow this until Oracle Junction where you turn left onto AZ Highway 77
Drive north approximately 6 miles on AZ Highway 77
Turn right on to Biosphere 2 Road at Mile Post 96.5
Please carpool. There will be parking in the Biosphere 2 parking lot, but it would help if participants carpooled to share the drive.