Delta Air Lines is throwing a rare one-day sale to a pair of Western destinations that make for an affordable and ideal spring, summer or autumn vacation.

A bargain round-trip rate of $222 is offered to Bozeman, Mont. and $272 to West Yellowstone, Mont.

To qualify, give at least a 21-day advance notice of travel. Trips are permitted seven days a week, based on sale seat availability.

When originating the trip Sundays-Wednesdays, a minimum stay of any three nights is required. Stay a minimum of one Saturday night when originating on other days.

Delta offers a nonstop flight from Atlanta to Bozeman each Saturday and will add an additional Thursday nonstop flight beginning June 7. Service to W. Yellowstone is via a flight connection in Minneapolis-St. Paul or Salt Lake City.

Taxes and fees are additional. Inclusive round-trip rates to Bozeman are $265.20 and $315.20 to W. Yellowstone (these destinations regularly price out near $550 round-trip outside of sale periods).

Now for the not-so-good news. This sale carries no ticket-by date which means the offers could vanish at any moment.

Sale airfares are always subject to change. Every seat on every flight is not offered at the lowest rate.

Since only a limited supply of seats is available, act quickly to make your purchase.

I recommend starting the search for available seats at Kayak.com vs. calling an airline directly. You can also search for the sale at travel Web sites such as Expedia or Travelocity, etc.

Adjacent to the West Entrance of Yellowstone National Park, West Yellowstone is the ideal base for an adventure getaway. Experience the full impact of the nation's first national park and over two million acres of nature's best. It's hard to run out of things to do in this area -- from fishing in blue-ribbon trout streams and lakes, hiking miles of trails for a closer look at flowers and wildlife, horseback riding with a western wrangler or a float trip on a gentle river or braving white water.

Bozeman is less than 100 miles north of Yellowstone National Park and is world-renowned for its fishing along the Madison, Gallatin and Yellowstone Rivers -- all within 30 miles of town. Hikers will have a tough time choosing from the numerous regional trails.

Clara Bosonetto is a retired travel consultant.