Yesterday, we noticed Delta drop prices on several routes for spring travel. Other airlines have matched this unadvertised sale today. Travel is valid any day/week through June 20, 2015.

Tickets appear to have a 21-day advance purchase requirement and some routes may require a Saturday night stay with a maximum stay of up to 30 days. This sale is unadvertised so it is unknown how long these fares will last. Some good deals can be found for travel on weekends as this sale includes Friday/Sunday travel, whereas, most sales usually don't.

Sample fares include:

Minneapolis/St. Paul to Detroit $214 round-tirp, nonstop

Minneapolis/St. Paul to Los Angeles $259 round-trip, nonstop

Duluth to $337 Las Vegas round-trip

Buffalo to Las Vegas $376 round-trip, nonstop

Columbus to Myrtle Beach $364 round-trip

Milwaukee to Columbus $286 round-trip

Salt Lake City to Phoenix $227 round-trip, nonstop

Minneapolis/St. Paul to Miami round-trip, nonstop

Houston to Minneapolis/St. Paul $197 round-trip, nonstop

Grand Rapids to Denver $294 round-trip, nonstop

Kalamazoo to New York $281 round-trip

Many more routes are included so search to see if your route has dropped for this travel period.

Above image via iStockphoto.com