Mount Rushmore may be one of South Dakota’s biggest draws, but there’s a sculpture just down the road that will eventually stand taller than the four colossal presidents.

With an estimated completion height of 563 feet, the memorial honoring Lakota leader Crazy Horse is on track to be one of the largest sculptures in the world. Someday. While the first blast occurred on June 3, 1948, the only identifiable thing that has emerged from the mountainside since then is a face.

Using dynamite to blast tons of pink granite is a tedious process, of course—one that has been slowed even more by Mother Nature. Crews working on the memorial have discovered seams and cracks in the underlying rock that have forced them to veer away from the original plan devised by sculptor Korczak Ziolkowski.

Another element that’s slowing the process is funding. Mount Rushmore sculptor Gutzon Borglum battled with federal officials over control and funds. Congress cut off funds in 1941 due to the war. Borglum died a week later, and some combination of the two events meant that the presidents’ bodies were never finished. Ziolkowski, already wary of government promises, watched the whole thing play out and vowed that his creation would be made without a penny of federal funding. Ziolkowski died in 1982, and decades later, his descendants have stayed true to that wish, using only admission fees and private donations to fund the project.

Even without the extensive delays, the project itself is not without controversy. Some Native Americans believe that the sculpture shouldn’t even exist, that defacing a mountain would go against everything Crazy Horse stood for. There’s also no authenticated photographic evidence of Crazy Horse, so some have issues with the accuracy of the depiction.

The Ziolkowski family is aware that Crazy Horse is taking longer than anticipated—their father had originally predicted 30 years—but they’re determined to go at their own pace. “[Korczak] said ‘Go slowly so you do it right,'” his late widow, Ruth, said in 2013. “And, I, for one, would like to have it go faster, but there are so many things that you have to do in order to do it right, that it takes the time."