Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Oct. 21, 2021
Registrant CIK	0000711034
Fiscal Year End	--12-31
Document Type	10-Q
Document Period End Date	Sep. 30, 2021
Entity File Number	001-08429
Entity Registrant Name	THUNDER MOUNTAIN GOLD INC
Entity Incorporation, State or Country Code	NV
Entity Tax Identification Number	91-1031015
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	83713-8986
City Area Code	208
Local Phone Number	658-1037
Title of 12(g) Security	Common Stock, $0.001 par value
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		60,855,579
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Document Quarterly Report	true
Document Transition Report	false
ExchangeOTCQB
Trading Symbol	THMG
Security Exchange Name	NONE
ExchangeTSXV
Trading Symbol	THM
Security Exchange Name	NONE