Kris Lane can’t shake the image of Christopher Columbus covered in blood.

Red fluid — all of it fake — ran down the famed explorer’s statue in downtown Denver after Native American activists emptied their buckets on Columbus Day 1989. Lane, a professor of Latin American history at Tulane University, lived in Denver then.

“The temper of the times was pretty different,” he recalled. “That initiated a conversation.”

Columbus Day controversy has flared up every fall since, this year with new fervor: Columbus statues from New York to Minnesota to California have faced vandalism or removal amid newly heightened debate on Confederate monuments, sweeping up the 15th century figure tied to genocide and slavery. In an age of toppling statues, what happens to Columbus?

While historians caution against lumping in Columbus with Confederates who came three centuries later, they say Columbus’ holiday and monuments remain ripe for reassessment — whether they stay, change or vanish entirely.