MAMMOTH CAVE, Ky. (AP) – Mammoth Cave National Park is offering free tours in honor of slain civil rights leader Martin Luther King Jr. The park can accommodate 70 people on each Mammoth Passage tour. The free tours on Jan. 20 will depart from the visitor center at 9:30 a.m., 10:30 a.m., 11:30 a.m., 12:30 p.m., 1:30 p.m. and 2:30 p.m. CST. The three-quarter-mile, 1 1/4-hour tour requires a walk down and up a steep path to the Historic Entrance and includes 160 steps. Tour participants must pick up their free tickets in the visitor center before the tour.