What is the Gateway Arch also known as?

I'm saying either Jefferson National Expansion Memorial or "The arch." I have heard it refered to also as gateway to the west.

Yes, Yafa. I have the Jefferson National Expansion Monument.

While it certainly is a monument, the National;Park Service, which runs the Gateway Arch, does not call it the Jefferson National Expansion Monument. The only term I find on its site is the Gateway Arch.

"Made up of the Gateway Arch, the Museum of Westward Expansion, and the Old Courthouse, this breathtaking national park reflects the spirit of the country's pioneers, and stands in tribute to Thomas Jefferson - the man whose dream inspired the spread of freedom and democracy from "sea to shining sea." - www.nps.gov/jeff.index

"Jefferson National Expansion Memorial consists of the Gateway Arch, the Museum of Westward Expansion, and St. Louis' Old Courthouse. During a nation-wide competition in 1947-48, architect Eero Saarinen's inspired design for a 630-foot stainless steel arch was chosen as a perfect monument to the spirit of the western pioneers. Construction of the Arch began in 1963, and was completed on October 28, 1965, for a total cost of less than $15 million. The Arch has foundations sunk 60 feet into the ground, and is built to withstand earthquakes and high winds; it sways up to 1 inch in a 20 mph wind, and is built to sway up to 18 inches. A Grand Staircase leads from the St. Louis levee up to the base of the Gateway Arch." - www.nps.gov/jeff/about

(emphasis mine- DG)

I could only find 'Gateway arch' and 'Gateway to the West.'

Those are more nicknames rather than the official name. By the way, I can see the Arch from the second floor of my house. The view from the observation windows at the top of the Arch is magnificent, but I won't go up again; the cable cars that you have to take up to get there are really small, smaller that the inside of a Mini Cooper. Not good for those of us who are volume-enhanced.