Image Credit: Stefano Salvetti/Getty Images

Given their way, some conservatives would jump at any chance to round out South Dakota’s iconic Mt. Rushmore with their hero 40th president, Ronald Reagan.

“Reagan was the most successful president of the 20th century,” Reagan Legacy Project Chairman Grover Norquist told Devin Dwyer of ABC News earlier this year. “He took a country that was in economic collapse and military in retreat round the globe and turned it completely around.”

Congress rejected the notion 12 years ago but the monument’s 70th birthday today is a reminder that the tribute to Washington, Jefferson, Lincoln and Roosevelt is incomplete with or without another face: The sculptor died before finishing Washington’s waist and coat, and Lincoln’s hands, according to the Rapid City, S.D.,  tourism website.

Here are some other things you might not know about the memorial to U.S. history:

* The project took 14 years and cost about $1 million;

* The carvings are scaled to people who would be 465 feet tall;

* Each head is 6 stories tall;

* The carvings displaced 800 million pounds of stone;

* The noses are 20 feet long;

* The workers climbed 506 steps each day. 

Sculptor Gutzon Borglum, who started the project at age 60, died unexpectedly seven months before the project was declared complete Oct. 31, 1941, built on his desire to “show posterity what manner of men they were. Then breathe a prayer that these records will endure until the wind and the rain alone shall wear them away.”