If there were a competition to find the nation’s most useless regulation, Idaho would have strong contenders. There’s a whole chapter of the administrative code devoted to snails that don’t live in Idaho. There’s a rule that explains the rules for a state lottery TV game show that has never existed.

Next week these superfluous regulations—and hundreds more—will disappear. Idahoans have legislative gridlock to thank. Each year state lawmakers reauthorize the administrative code, but this spring, after a spat between the House...