The park visitor center is open daily from 9 a.m. till 5 p.m. The memorial is open from 9 a.m. till 4:45 p.m. (Times are Eastern time. Terre Haute to the north is located within the Eastern Time Zone while Evansville to the south is within the Central Time Zone.  All of Illinois is within the Central time Zone.) The park is closed Thanksgiving, Christmas, and New Year's Day.

Visitors should be aware that Vincennes and Knox County observe central time and during the spring of 2005  started to observe daylight savings time.  Counties to the north observe eastern time while some counties to the east and southeast are on central time. Indiana Time Zone map at  http://www.in.gov/core/files/Timezonespring.pdf