Scenic Drive to Mount Rushmore National Memorial, USA - 4K Video with a Riddle!

This driving video is a scenic loop drive amid wild nature surrounding Mount Rushmore National Memorial. Then we arrive at the Mount Rushmore National Memorial parking lot. In the final part of the video there's a slideshow with a bonus riddle! Please write your results in the comment section below!
You can also watch driving video to Devils Tower National Monument: • Devils Tower, Wyoming,...
Mount Rushmore National Memorial is centered on a colossal sculpture carved into the granite face of Mount Rushmore in the Black Hills near Keystone, South Dakota. Sculptor Gutzon Borglum created the sculpture's design and oversaw the project's execution from 1927 to 1941 with the help of his son, Lincoln Borglum. The sculpture features the 60-foot-tall (18 m) heads of four United States Presidents recommended by Borglum: George Washington (1732-1799), Thomas Jefferson (1743-1826), Theodore Roosevelt (1858-1919) and Abraham Lincoln (1809-1865). The four presidents were chosen to represent the nation's birth, growth, development and preservation, respectively. The memorial park covers 1,278 acres (2.00 sq mi; 5.17 km2) and the actual mountain has an elevation of 5,725 feet (1,745 m) above sea level.
Historian Doane Robinson conceived the idea for Mount Rushmore in 1923 to promote tourism in South Dakota. In 1924, Robinson persuaded sculptor Gutzon Borglum to travel to the Black Hills region to ensure the carving could be accomplished. Borglum chose Mount Rushmore partly because it faced southeast and enjoyed maximum exposure to the sun.
Borglum said upon seeing Mount Rushmore, "America will march along that skyline." Borglum believed that the sculpture should have broad appeal and chose the four presidents.
Peter Norbeck, U.S. senator from South Dakota, sponsored the project and secured federal funding. Construction began in 1927; the presidents' faces were completed between 1934 and 1939. After Gutzon Borglum died in March 1941, his son Lincoln took over as leader of the construction project. Each president was originally to be depicted from head to waist, but lack of funding forced construction to end on October 31, 1941.
The carving started in 1927 and ended in 1941 with no fatalities.
Sometimes referred to as the "Shrine of Democracy", Mount Rushmore attracts more than two million visitors annually.
en.wikipedia.o...