San Pedro River BioBlitz

Arizona

View of a mountain range on a sunny day with clouds above and green trees and brush in the foreground. — Middle San Pedro © Ryan Olinger

Event Overview

The San Pedro River BioBlitz is a community-based event where participants record as many plant and animal species as possible within the San Pedro River watershed throughout the month of November. Locals, visitors and nature enthusiasts of all ages are welcome to participate in the San Pedro River BioBlitz by using the free iNaturalist app to photograph and identify species across the watershed.

TNC and partners will also be hosting a series of events throughout the month where people can gather for nature walks and demonstrations to learn more about local ecology and conservation efforts. Bioblitz observations will be verified by a team of local scientists, ensuring that all entries contribute to our understanding of regional biodiversity.  Find TNC and partner events below.

San Pedro Watershed

One of the last free-flowing rivers in the American Southwest

DATE

Nov 01, 2025 – Nov 30, 2025

MT (UTC -06:00h)

The  San Pedro River  flows approximately 175 miles from its headwaters in Sonora, Mexico to its confluence with the Gila River. The river and its tributaries span the Sierra Madres in Mexico and the Sky Islands of southern Arizona while bridging the Chihuahuan and Sonoran Deserts and connecting the towns of Palominas, Hereford, Sierra Vista, St. David, Benson, Cascabel, Huachuca City, Reddington, Tombstone, San Manuel, Mammoth, Dudleyville and Winkleman. 

Map showing the Upper and Lower San Pedro Watershed. — **The San Pedro River watershed is a remarkable place to connect with nature.** Surrounded by public lands including the San Pedro Riparian National Conservation Area (4), Coronado National Forest and Bureau of Land Management; this region offers countless opportunities for exploration. While hiking trails abound, accessibility matters. Parks and preserves with ranger support provide welcoming, inclusive ways for people of all abilities to experience the outdoors. Oracle State Park (1), Kartchner Caverns State Park (2), Ramsey Canyon Preserve (5) and Coronado National Memorial (3) are all located within the San Pedro River watershed. © TNC

iNaturalist Training Webinar hosted by Pinal County—November 2nd from 4-5 p.m. on Google Meet. Join the video call here.
Adobe Nature Walk hosted by TNC—November 8th from 9-11 a.m. at 2890 S Pz Ranch Rd, Dudleyville, AZ. 18+ register here.
Wildlife Camera Workshop hosted by TNC—November 12th from 9-11 a.m. at TNC's Ramsey Canyon Preserve (27 E Ramsey Canyon Rd, Hereford, AZ 85615). Register here.
Kids Macroinvertebrates Workshop hosted by ADEQ’s AZ Community Science Alliance—November 12th from 1-3 p.m. at TNC's Ramsey Canyon Preserve (27 E Ramsey Canyon Rd, Hereford, AZ 85615). Register here.
Middle San Pedro Preserve Bird Walk hosted by Tucson Bird Alliance—November 15th from 8-10 a.m. at TNC's Middle San Pedro Preserve (4212 N Cascabel Rd, Benson, AZ 85602). 18+ register here.
Dudleyville Park BioBlitz hosted by Pinal County—November 15th from 9-11 a.m. at 4004 N Dudleyville Road, Dudleyville, AZ 85192. No sign-up; reach out to jasmine.guillen@pinal.gov with questions.
Middle San Pedro Preserve Bird Walk for Families hosted by Tucson Bird Alliance—November 15th from 10 a.m.-12 p.m. at TNC's Middle San Pedro Preserve (4212 N Cascabel Rd, Benson, AZ 85602). Register here.
Oracle Community Park BioBlitz hosted by Pinal County—November 15th from 1-3 p.m. at 333 E Nuestro Street, Oracle, AZ 85623. No sign-up; reach out to jasmine.guillen@pinal.gov with questions.
Nature Walk with Friends of the San Pedro (FSPR)—November 16th from 8-11 a.m. at the FSPR House (9800 AZ-90, Sierra Vista, AZ 85635). No sign-up; reach out to Robert Weissler at weissler@aves.org with questions.
Tiger Mine Trailhead Nature Walk hosted by Pinal County—November 22nd from 9-11 a.m. at Tiger Mine Trailhead (24950 Tiger Mine Rd, Oracle, AZ 85618). Contact jasmine.guillen@pinal.gov to sign up.
Kartchner Caverns State Park BioBlitz—November 22nd from 8 a.m.-5 p.m. at Kartchner Caverns State Park (2980 AZ-90, Benson, AZ 85602). Pay at gate.
Canelo Hills Cienega Preserve Bird Walk hosted by Audubon SW—November 24th from 9-11 a.m. at TNC's Canelo Hills Cienega Preserve (park at 31.554592 N 110.527145 W). Register here.

View the San Pedro BioBlitz iNaturalist Project and watch the video below to learn how to use the app.

Questions? Contact Southern Arizona Water Projects Coordinator Haylee Short at haylee.short@tnc.org.

How to Make an Observation on iNaturalist (1:24) A quick video demonstrating how easy it is to make an observation with the iNaturalist mobile app.