This is a new nonstop route for Frontier, which begins August 12, 2018. The $39 roundtrip sale Frontier had earlier this week has stuck around through today so book now for a super cheap getaway later this summer.
As an example, I found this price available departing Sacramento SMF on Tuesday, August 14, returning from Las Vegas on Thursday, August 16. Longer trips are available as well, for travel on Tuesdays and Thursdays, from mid-August through mid-September.
Keep in mind, Frontier charges extra for any bags larger than a small personal item. Checked bag fees for this travel period start at $30 each way. Larger carry-on bag fees start at $35 each way.
It's perfectly feasible to jet down to Vegas for few nights with just a small backpack, but adding a checked bag to this fare is still under $100 total roundtrip, which is cheaper than any other option. Nonetheless, if you prefer to avoid Frontier, you can fly on Southwest for $158 roundtrip.
Need a room in Vegas? Here's what's available for the listed dates above on Hotelwatchdog.