With time on my hands in the passenger seat heading home on 395 after climbing Tom, I learned from an old USGS report found online:
The ore mined at Tungstar was discovered in 1937. Production started in November 1939, using a 2.6 mile tram to a mill near the junction of Pine and Gable creeks at about 7400 feet. Production ended in October 1946, when the mine installations and upper tram terminal burned; the mill and office buildings were destroyed by a 1951 snow slide. The quality of the ore deteriorated from about 2.7% tungsten trioxide early on to less than 1% toward the end. (Searching "Tungstar Mine usgs" should turn up a link to the report, which has many obscure details--ever wonder what a glory hole is?)
As of 1948 (judging by the date on one of the report's drawings): "The best means of access to both mines is by Jeep, driving up the Hanging Vallay mine road. This road follows Horton Creek, on the south side of Mt. Tom, to Horton Lake then switches spectacularly up a steep 2,000-foot high escarpment north of the lake."