Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Jun. 30, 2017	Mar. 26, 2017
Document and Entity Information
Entity Registrant Name	Thunder Mountain Gold Inc
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Entity Central Index Key	0000711034
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Entity Common Stock, Shares Outstanding			57,133,879
Entity Public Float		$ 4,599,851
Entity Incorporation, Date of Incorporation	Nov. 09, 1935
Trading Symbol	thmg