Las Vegas - Any idea on why flights from DEN to LAS are so expensive 6/23 - 6/26?

I can't seem to find any reason the flights are almost double what they typically are out of Denver. Usually we can do the quick flight to Vegas for $150 or so, but they are well over $300 for a non-stop at a reasonable time. Any ideas?

Thanks!

Lot happening that week:
http://www.lasvegastourism.com/conventions_jun.htm

If you've not already purchased, check again now. SW started a fare war late Tuesday with $54/ow rates. Frontier, CO/UA have matched.

Thanks for the heads up, but they are still just as expensive. The pricewar doesn't seem to have affected the price for my dates.

In addition to the conventions, the world series of poker is on.