When completed, the 10-meter W.M. Keck Telescope will be the world's largest instrument for optical and infrared astronomy. It has twice the diameter and four times the light-gathering power of the famous Palomar Observatory 5-meter Hale Telescope. Because of its size and required precision, it has presented many challenges in manufacturing and transportation to site. This paper reports on the progress of the construction of the telescope structure supplied by TIW Systems. At the time of this paper approximately ninety-five percent of all fabrication is complete and all major subassemblies have been proof assembled and passed shop testing. Site installation of the azimuth bearing journal is underway.