found: Work cat.: 96130156: Secrets of Si, c1995:p. 11 (Mt. Si, known worldwide as Twin Peaks; known to local Indians as Kelbts)
found: BGN, April 30, 1996(Si, Mount, summit, King County, 47⁰30ʹN, 121⁰44ʹW; also 5 Twin Peaks as summits, one in King County)
found: Washington place names database, via WWW, Apr. 12, 2000(Mount Si is a peak with an elevation of 4,190 feet two and a half miles northeast of North Bend in east central King County. The name appears as Si Mountain on some maps.)
found: BGNsummit; 47°30ʹ00ʺN 121°44ʹ00ʺW
notfound: Lippincott;Rand McNally;Web. geog.;Columbia gaz.