In 1882 James MacKinlay of Kamloops found a deposit of mica on this mountain. The fifteen-foot wide vein of fair grade, light green muscovite was to tantalize various miners for the next several years. In 1887 John Fremont Smith of Kamloops organized an expedition which included Louis, chief of one of the Shuswap (Secwépemc) bands, and a number of his retainers. With ever-changing crews, Smith pegged away at what he called his Bonanza Mine until at least 1899. In 1912 Smith was appointed agent for the Kamloops Indian Agency, which included the North Thompson [1].

In 1900 James McEvoy [1862–1935] indicated a mica mine on the north-east slope of Mica Mountain:

On the south-west side of the valley, opposite Tête Jaune Cache, on Mica Mountain a great series of mica-schists are found dipping S. 45° W. at angles of 30° to 50°. This series includes dark glittering mica-schist, easily weathering, thinly foliated garnetiferous mica-schist, with a high percentage of mica and garnet, hard garnetiferous micaschist in massive beds, bands of dark fine-grained micaceous rock apparently of eruptive origin, and layers of fine-grained gneiss which in some instances at least, is certainly intrusive.

The ordinary constituents of these are, quartz, triclinic felspar and c muscovite. In addition to these they sometimes contain tourmaline, I garnet, cyanite, beryl and apatite. Dr. Hoffmann has kindly examnined many of the mineral specimens collected, and has determined these. On one of these veins, seven miles south of Tête Jaune Cache, the Bonanza mica mine is located. It is 5,300 feet above the level of the Fraser River. Where an opening has been made, the veins is about fifteen feet wide dipping S. 15° W. < 40°, with the schists. The mica is a transparent muscovite with a very slight greenish cast, and of excellent quality. While little work has been done with a view to proving the extent of the deposit, it may reasonably be expected, from what actually appears, that a large quantity of mica can be obtained here, and the probabilities of further important developments appear to be very favourable. Thirty feet below the Bonanza vein, is another vein of pegmatite, forty feet thick. A few miles to the south-east across an intervening ridge, another claim has been located by some Edmonton miners, but no work was in progress and the place was not visited [2].

Frederick Arthur Ambrose Talbot [1880–1924] travelled through the area in 1910 with a party of Grand Trunk Pacific Railway employees. He wrote,

Certainly there is plenty of scope for development in all sorts of ways. The mountains teem with minerals of all descriptions, Keller showing us specimens of galena, gold, silver and other valuable metals, claims for which he had staked out. Mica Mountain is a great storehouse of mica, and some of the mineral obtained from it is quite noteworthy. It is white, and of good cleavage, and sheets from 32 inches square upwards can be readily obtained. If such veins are extensive, the mica mining prospect here is brilliant indeed. About twenty claims have already been staked, and the large block of this mineral which carried off a distinguished award at the last Paris Exhibition was mined on this mountain. When the neighbourhood becomes more accessible, prospectors will pour into the country, and carry out their task upon a broad, scientific basis, whereas up to the present only the surface here and there has been scratched. The wealth in the mountains hereabouts is beyond human conception, and, after the experience of Cobalt, he would be a rash man indeed, no matter what his geological and other qualifications might be, who would dare to say what could not be found [3].