In response to recent concerns about gastrointestinal illness along the Arizona Trail and potential causes being the Gila River and Remote Rainwater Collector, the ATA took water samples to a local laboratory for analysis. Results can be found here:

• Gila River – Passage 16
• Rainwater Collector – Passage 17

The only alarming result is the presence of E. coli in the Gila River. This is no surprise, since cattle are found in abundance along the river. A recent survey also found a dead cow decomposing upstream of the location where most AZT travelers fill and filter bottles. These test results are a reminder that all water sources should be treated before drinking, especially when hiking or riding in cattle country.

Testing water for the presence of norovirus was not possible, and is also extremely unlikely as norovirus is most commonly transmitted from person-to-person (according to epidemiology experts at the Arizona Department of Health Services). Studying the occurrence of norovirus on the AZT is ongoing, and results from the recent Sick Hiker Survey are anticipated in June 2025.