CHICAGO (AP) — Amtrak is offering discounted tickets for passengers traveling to southern Illinois to view the upcoming total solar eclipse.

A coast-to-coast total solar eclipse — where day briefly becomes night — will occur in the U.S. on Aug. 21 for the first time in 99 years.

It’ll last the longest near Carbondale, Illinois. That’s where thousands of people are expected to gather to experience less than three minutes of darkness, along with a festival and other activities planned by area communities.

Amtrak is a sponsor of the Carbondale Eclipse event.

The rail service says passengers heading to the area on the Illini or Saluki trains between Aug. 16 and 22 may save 30 percent on tickets. The routes make various stops between Chicago and Carbondale.