Community members are invited to participate in the 25th annual Snapshot Day, a citizen science event taking place on Saturday, May 10.

Volunteers will help collect and test water samples from locations across the Truckee River watershed, including creeks, streams, smaller lakes, and Lake Tahoe.

The goal is to capture a single-day “snapshot” of water quality for this key regional water source.

The nonprofit organization Keep Tahoe Blue is organizing volunteer teams to monitor sites along the South Shore of Lake Tahoe, from Meeks Bay to Zephyr Cove and extending to the headwaters of the Upper Truckee River.

Sampling tasks will include testing for parameters such as dissolved oxygen, pH, and nutrient levels.

Volunteers of any age and experience level are welcome to participate.

Individuals may register to join an existing team, form their own team with others, or serve as a team leader.

Those opting to lead a team are required to attend a training session that focuses on procedures for accurate data collection.

The Team Leader Training will take place on Wednesday, May 7, from 5:00 to 7:00 p.m. at the Lake Tahoe Community College Board Room.

The main event will run on Saturday from 9:00 a.m. to noon, followed by lunch, a raffle, and a celebration from noon to 1:00 p.m.

Volunteers will gather at the Lake Tahoe Community College Gym at 1 College Drive in South Lake Tahoe, before traveling to their assigned monitoring locations.

Snapshot Day has been held annually since 2001, making it the longest-running citizen science event of its kind in the region.

It covers areas from Meyers through North Lake Tahoe and continues downstream to Truckee, Reno, and Pyramid Lake.

By testing the same sites each year, organizers track long-term trends in water quality.

The event is also designed to foster a connection between the community and the local environment through direct participation in scientific fieldwork.

Registration for general volunteers is available at keeptahoeblue.org/ssd-2025, and registration for team leaders is available at keeptahoeblue.org/ssd-leader.

A map of last year’s results and more information about Snapshot Day can be found at keeptahoeblue.org/ssd.