Leduc County issued a stop order to the Mad Hatter Music Festival on Thursday after organizers said they planned to go ahead, even though they lack permission to do so.
A peace officer posted the notice at the festival entrance just before noon after he was unable to track down any of the organizers.
Events were supposed to start at noon but they have now been pushed back to 4 p.m. The county is expected to return later on Thursday afternoon.
On Wednesday, officials with the county south of Edmonton denied organizers permission to proceed because they failed to provide adequate information about emergency plans, health permits and additional security.
Sarah Dantzer, head planner for the festival, told CBC News that the event was going ahead as planned. County officials said they were prepared to intervene.
"The event continues to be unsanctioned by Leduc County and we still have some very serious concerns about the health and safety of those who will be attending the festival," said county spokeswoman Leila Daoud.
"As well as monitoring the situation closely, Leduc County is going to hand deliver an official stop order to festival organizers today."
Dantzer says she has checked with lawyers. She has also been in contact with RCMP and Leduc County but wouldn't elaborate.
"I know what could happen in my decision to continue moving forward and I am prepared for those consequences," she said.
She said she was surprised when Leduc County sent out a news release on Wednesday announcing the festival didn't have permission to go ahead.
She denies that the county wasn't provided with adequate information.
The festival is taking place on private property from Aug. 23 to 27.