I thought these had gone away, but this company still runs them 3 times a week. They are free but charge a $5 fuel surcharge, so in this context $5 is the new free.
Still a great deal as long as you like going for just a few hours.
Some like Laughlin. Some hate Laughlin.
But here is the website of the company. I did not find the tour listed there, but called the 800 number in the upper right corner which you should do to book it.Las Vegas Sightseeing Bus Tours -Sightseeing Tours Unlimited