I, too, have never seen it on a map, although it has been called that for well over 50 years. Secor doesn't mention it; I believe because it's merely a small bump on Irvine's NE ridge, so hardly a "mountain."
But it's a fine climbing objective. It was listed in Roper's 1976 High Sierra guidebook (as 12,000'+), and in Voge's prior 1954 guidebook (also as 12,000'+, although he called it Mount Candlelight). Both of these were the "official" Sierra Club guidebooks of the time, as I believe Secor's is now.
I know of at least 7 routes on it, ranging from class 2 to III, 5.6, A2. My favorite is the fine, exposed, class 3 east ridge, accessed from Lone Pine Lake.
On the 7.5 min metric topos, it shows above the 3720 m line but below 3740 m. So I've been calling its elevation 12,240'.