Update: River Fire in Kern County close to full containment

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Updated: 11:15 a.m. May 21

First discovered: 3 days ago, 8:27 a.m. May 18

Initial location: State Route 178 Mouth of the Canyon, East of Bakersfield, Kern County, Calif.

Fire unit: Unified Command: Cal Fire, Kern County Fire Department and Sequoia National Forest

Fire type: Wildfire

Fire name: River Fire

River Fire initially started 8:27 a.m. May 18 on State Route 178 Mouth of the Canyon, East of Bakersfield in Kern County, California.

It has burned 3,535 acres after being active for three days. By Thursday noon, the fire crew managed to contain 90% of the fire. The cause is, however, still being investigated.

Fire containment

What does it mean for a fire to be 90% contained?

The percentage indicates how much of the fire perimeter has been surrounded by a control line. In this case, it means that 90% of the wildfire is contained from spreading, while 10% is still uncontrolled.

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: Cal Fire

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This story was originally published May 21, 2026 at 11:26 AM.