Since 1999, The Nature Conservancy has conducted annual wet-dry mapping of the entire 170-mile length of the San Pedro River. This takes place on the third Saturday of June with the help of many volunteers and our local, industry, state and federal agency partners throughout the watershed. On that day, small groups of volunteers will map all the way from the headwaters in Sonora, Mexico down to the confluence with the Gila River in Pinal County, Arizona, as well as many major tributaries.
We are looking for volunteers to help us map on June 15, 2019. This entails joining a small team of 2-4 people to map a 2- to 6-mile reach of the river or tributary. Mapping begins in the early morning and goes into early afternoon (depending on the reach), because mid-June is typically the driest, hottest pre-monsoon time of year. Volunteers use GPS units (provided) to document where surface water is present or absent. This information will be analyzed with other data to help water managers and scientists gauge the health of the river. Having an annual record also gives us a way to compare from year-to-year how management decisions are working.