Hurry, this deal only lasts 72 hours! Come October 20 at 11:59 p.m. Pacific Time say goodbye to air fare as low as $35 one-way on Southwest and AirTran.

Rules for these two sales are similar, as AirTran is a subsidiary of Southwest. Travel with tickets purchased in the next three day, from Nov.30 to Dec. 14, 2011 and ring in the New Year from Jan. 4 to Feb. 15, 2012.

These tickets do block out peak holiday travel, but with deals this low, passengers may be able to get more family time, sneak away from the first snow, or get some January skiing in out west.

One snag is that Sunday flights do not apply, ruining the chance of a weekend getaway (guess you'll have to take off Monday too).

Flights for both sales are broken down by distance starting at $35 for travel 450 miles or less, $65 for 451-1,000 miles, $95 gets 1,001-1,500 miles, and for those trips over 1,5001 miles it will cost $125.

For example a traveler from Los Angeles on Southwest can get a $35 flight to places such as Las Vegas, Seattle, or San Francisco. For $65 those same Los Angeles passengers can get to Salt Lake City or Tucson, spring for $95 to get a bit further to Austin or Little Rock. $125 will get to the other side of the U.S. to cities like Charleston, New Orleans, or Nashville.

Sale seats are limited, so it's best to book at the start of the sale. For more of the fine print and to see destinations from each city visit the airlines' official Web site.