The Republican initially pushed the Legislature to move the law's June expiration to 2021, but lawmakers instead sent him a bill that removed the sunset.
The law passed in a special legislative session last year. It restored access to nearly 30 specific lakes for public recreation hampered after a 2017 state Supreme Court decision.
The law also said lakes on private property are open for recreational use unless a landowner installs signs or buoys saying an area is closed.
Daugaard writes in a column that officials have brought certainty and found an "answer that is working for landowners and sportsmen."
The governor's office says Daugaard signed the bill into law Friday.
© 2018 Associated Press. All Rights Reserved. Material may not be redistributed.
Gov. Dennis Daugaard has signed a bill to make permanent an expiring law that governs the use of lakes on private land for recreation.