The Gateway Arch Low-poly 3D model is available on CGTrader for $30. Original author: Renatas. Specs: 322 polys, 300 verts.
BLEND (Blender, filesize: 326 KB), OBJ (OBJ, filesize: 135 KB), FBX (Autodesk FBX, filesize: 119 KB), 3DS (3D Studio, filesize: 103 KB), DAE (Collada, filesize: 257 KB), STL (Stereolithography, filesize: 108 KB)