Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Feb. 15, 2022	Jun. 30, 2021
Document Information [Line Items]
Registrant Name	Thunder Mountain Gold, Inc.
Registrant CIK	0000711034
Fiscal Year End	--12-31
SEC Form	10-K
Period End date	Dec. 31, 2021
Tax Identification Number (TIN)	91-1031015
Number of common stock shares outstanding		60,855,579
Public Float			$ 5,459,564
Filer Category	Non-accelerated Filer
Current with reporting	Yes
Interactive Data Current	Yes
Voluntary filer	No
Well-known Seasoned Issuer	No
Shell Company	false
Small Business	true
Emerging Growth Company	false
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-08429
Entity Incorporation, State or Country Code	NV
Entity Address, Address Line One	11770 W. President Dr., Ste. F
Entity Address, City or Town	Boise
Entity Address, State or Province	ID
Entity Address, Postal Zip Code	83713
City Area Code	208
Local Phone Number	658-1037
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Auditor Name	Assure CPA LLC
Auditor Location	Spokane, Washington
Auditor Firm ID	444
ExchangeTSXV
Document Information [Line Items]
Trading Symbol	THM
Trading Exchange	NONE
Title of 12(g) Security	Common Stock, $0.001 par value
ExchangeOTCQB
Document Information [Line Items]
Trading Symbol	THMG
Trading Exchange	NONE
Title of 12(g) Security	Common Stock, $0.001 par value