Document and Entity Information - shares	6 Months Ended
	Jul. 31, 2016	Sep. 07, 2016
Document and Entity Information
Entity Registrant Name	MESABI TRUST
Entity Central Index Key	0000065172
Document Type	10-Q
Document Period End Date	Jul. 31, 2016
Amendment Flag	false
Current Fiscal Year End Date	--01-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		13,120,010
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2