Earth Day 5K at Biosphere 2

Sat April 23, 2022 Oracle, AZ 85623 US Directions

Earth Day 5k Run/Walk

$30 8:30AM MST - 11:00AM MST
955 spots left. Price increases after January 31, 2022 at 11:59pm MST
Event Website

Additional event information can be found at

32540 S. Biosphere Road
Oracle, AZ US 85623

Run the Desert . . . then visit a rain forest, view an ocean reef, and wander through savanna grass lands . . . all in one day!

Join us at the inaugural EarthRun 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 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.

To ensure a unique experience, the race is capped at 1,000 registrants -- all registrants receive these cool swag items:

  • souvenir race shirt
  • commemorative race medal
  • official finisher's time with chip timing
  • free entry to the world-famous Biosphere 2
  • post-race snacks and goodies

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

Weather: 50's - 70's

Differently Abled: Yes, be mindful of hills and dirt road

Pets Allowed: No

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

Saturday, April 23rd Planned Schedule:
7:30-8:15 Race day registration and packet pick up
8:30 Start time for Earth Day 5k Run/Walk
9:45 Free Kids Dash
10:15 Awards 
Ongoing Earth Day Festival. 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.

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

Questions? Contact Race Director Randy Accetta at  


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