California has banned all fishing on a section of the American River near Folsom to help protect fish populations.
The concern is there is not enough water for them to migrate and spawn.
The emergency regulations went into effect this week, complete with signs up-and-down the river.
Some fishermen said they saw the signs and turned around, but not everyone is playing by the rules.
"We were actually next to a couple," American River visitor Janel Halteh said. "We actually saw them. There was a big fish that they had caught."
"I think it's irresponsible to fish when they've been asked not to, and yet, they are standing right there," another visitor Edna Berlier said. "They are standing there fishing."
Catching any fish in the restricted areas is a misdemeanor that comes with a fine of up to $1,000.