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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)
12 Months Ended
Jan. 31, 2013
t
Jan. 31, 2012
Cash and Cash Equivalents    
Amount held by the Trust in a money market fund $ 6,727,461 $ 10,253,474
Revenue Recognition    
Quantity of iron ore shipped by NMC subject to price determination recognized in revenue (in tons) 717,000  
Fixed Property, Including Intangibles    
Percentage of fee interest owned by Mesabi Land Trust in the lands subject to the Peters Lease 20.00%