Traffic was snarled on both sides of the 15 Freeway.
A city spokeswoman estimated at least 3,000 visitors showed up before noon.
RELATED: Lake Elsinore officials announce $10 shuttle service fee to Walker Canyon
To try to cut down on the congestion, the city is now requiring visitors to pay for $10 shuttles to get to Walker Canyon on weekends.
The buses are running every few minutes until 8 p.m.
Last weekend, public safety officials had to close access to the canyon due to the amount of people.