James Novak, 28, of Cloverdale, was taken into custody in a remote area near Pine Flat Road after a group of four hunters said they saw him start a grass fire, according to the Sonoma County Sheriff's Office.
Novak allegedly told the hunters he was starting a controlled burn, the sheriff's office said.
They detained Novak until the sheriff's office responded and took him into custody.
The fire burned approximately one acre before it was contained, a Cal Fire dispatcher said.
Novak is suspected of starting several other fires in Sonoma County on Saturday, including one that burned approximately 21 acres near Dutcher Creek Road at around 3:30 p.m., the sheriff's office said.
A witness apparently saw a man throwing lit flares out of a vehicle that was registered to Novak, according to the sheriff's office.
Deputies searched the area and went to Novak's Cloverdale residence on North Jefferson Street but were unable to locate him until today.
A fire that started behind Novak's residence on Saturday was also under investigation, the sheriff's office said.
No structures were damaged and no one was injured as a result of the suspicious fires, the sheriff's office said.
The case remains under investigation by Cal Fire and the Sonoma County Sheriff's Office.