Update: 5-3 Fire in Tuolumne County remains fully contained by Friday morning

Published Sep 26, 2025 #5-3 fire

Updated: 7:49 a.m. Sep. 26

First discovered: 24 days ago, 10:16 a.m. Sep. 2

Initial location: Tuolumne County, Calif.

Fire type: Wildfire

Fire name: 5-3

5-3 Fire initially started 10:16 a.m. Sep. 2 in Tuolumne County, California and it is a part of TCU SEPTEMBER LIGHTNING COMPLEX fire.

It has been burning on private land for 24 days. As of Friday morning, the fire has been fully contained. The cause remains undetermined.

Fire containment

What does 100% containment mean?

Note that full containment doesn’t mean the fire is completely out. In this case, it means that the wildfire has been fully enclosed by a control line and it is now stopped from spreading. A fully contained wildfire may continue to burn within the containment perimeter but is not likely to spread.

However, there’s a significant difference between containing and controlling a wildfire. After the fire is fully contained, the next step is to control it. Controlling a fire means ensuring that the fire can’t spread or cross the containment line.

Containment is part of a larger plan for managing a wildfire. It is normally expressed as a percentage and it refers to how much of the fire perimeter has been surrounded/enclosed by a control line that firefighters create. The containment percentage indicates a certain level of control, but it doesn’t always correlate to safety level. Also, it’s important to note that containment doesn’t mean a fire is out.

How is containment measured?

The incident’s central command constantly receives progress reports from firefighters on the ground. As the fireline is constructed, inspected or reinforced, mappers record those details to adjust the containment percentage. The percentage tells the public how much of the fire perimeter is believed to not go beyond the control lines.

Source: National Interagency Fire Center