They sell Tonto passes for the lake/river! David D. 79¢ drinks all the time.

Can I buy a Tonto Pass at Canyon Lake?

Tonto National Forest - Canyon Lake. District Ranger offices are open to the public for in person transactions. Tonto Passes can be purchased at a district office or from a local retailer.

What is the fine for not having a Tonto Pass?

While a Tonto Pass is not required throughout the entire Tonto National Forest, the fine is $100 if you don't have a valid pass in the required areas. Considering the pass costs less than $10 a day, it's probably better to be safe than sorry.