Deposit

Unnamed (upper Idaho Gulch)

Unnamed (upper Idaho Gulch) is a deposit with published resource estimates in Alaska, recorded in the USGS USMIN rare earth element occurrence database (ver. 4.0, June 2019).

Facts on this page last re-verified Aug 12, 2026 — the oldest verification date among its current claims. How we verify.

Location: Alaska, United States (65.930, -150.937 approx.)

Commodities: niobium; silver; rare earth elements; uranium; zirconium; phosphorus pentoxide

Deposit model: carbonatite · carbonatite deposits

Published resource estimates

As compiled by USGS USMIN from the cited studies. Resource classes follow the source; "approximate" flags values USMIN reports as approximations. These are not current company reserve statements.

Material	Class	Amount	Grade	Contained	As of	Reference
phosphorus pentoxide (P2O5)	Inferred	≈222,000 t	5 percent	11,100 metric tons P2O5	Jan 1, 1986	Warner and others (1986), Page 16 — Warner, J.D., Mardock, C.L. and Dahlin, D.C., 1986, A columbium-bearing regolith on upper Idaho Gulch, near Tofty, Alaska: U.S. Bureau of Mines Information Circular 9105, 29 p.
niobium (Nb)	Inferred	201,000 t	0.07 percent	141.1 metric tons Nb	Jan 1, 1986	Warner and others (1986), Page 16 — Warner, J.D., Mardock, C.L. and Dahlin, D.C., 1986, A columbium-bearing regolith on upper Idaho Gulch, near Tofty, Alaska: U.S. Bureau of Mines Information Circular 9105, 29 p.
niobium (Nb)	Indicated	19,400 t	0.07 percent	13.6 metric tons Nb	Jan 1, 1986	Warner and others (1986), Page 16 — Warner, J.D., Mardock, C.L. and Dahlin, D.C., 1986, A columbium-bearing regolith on upper Idaho Gulch, near Tofty, Alaska: U.S. Bureau of Mines Information Circular 9105, 29 p.
zirconium (Zr)	Inferred	≈222,000 t	0.07 percent	156.1 metric tons Zr	Jan 1, 1986	Warner and others (1986), Page 16 — Warner, J.D., Mardock, C.L. and Dahlin, D.C., 1986, A columbium-bearing regolith on upper Idaho Gulch, near Tofty, Alaska: U.S. Bureau of Mines Information Circular 9105, 29 p.

Exploration and site history

Exploration — Approximately 12,000 ft of trenching, comprising 40 trenches, and 1,400 ft of diamond drilling were completed in the headwaters of Idaho Gulch at that time, 1956 (Warner and others (1986))
Discovery — It was originally identified in 1956 by the Bureau as a result of investigations to locate lode sources of tin, columbium, tantalum, chromium, and radioactive minerals found in placer gold deposits of the Tofty area, 1956 (Warner and others (1986))

Record imported from USGS USMIN ver. 4.0 (June 2019). Developments after that date appear on facility records, not here; see the methodology.

Sources

U.S. Geological Survey · published Jun 1, 2019 · retrieved Aug 12, 2026 · archive unavailable: Wayback snapshot 20260427015518 of the ScienceBase item exists but the archive service returned 503 on verification 2026-08-12; recheck on a weekly pass