Note 18 - Supplemental Cash Flow Information (Details Textual) - USD ($)	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Interest Paid, Excluding Capitalized Interest, Operating Activities	$ 1,626,667	$ 1,622,222	$ 1,622,222
Stock Issued During Period, Value, Acquisitions			$ 23,771,623
Reno Creek Project [Member]
Stock Issued During Period, Shares, Acquisitions (in shares)			14,634,748
Payments to Acquire Businesses, Gross			$ 909,930
Stock Issued During Period, Shares, Issued for Reimbursable Acquisition Expenses (in shares)			353,160
Stock Issued During Period, Value, Issued for Reimbursable Acquisition Expenses			$ 483,829
Stock Issued During Period, Shares, Transaction Costs (in shares)			217,702
Stock Issued During Period, Value, Transaction Costs			$ 283,013
North Reno Creek Project [Member]
Stock Issued During Period, Shares, Acquisitions (in shares)			1,625,531
Stock Issued During Period, Shares, Transaction Costs (in shares)			65,684
Stock Issued During Period, Value, Transaction Costs			$ 105,751
Stock Issued During Period, Value, Acquisitions			2,617,105
Payments to Acquire Assets, Gross			$ 2,940,000
Diabase Project [Member]
Stock Issued During Period, Shares, Acquisitions (in shares)			164,767
Stock Issued During Period, Value, Acquisitions			$ 232,321
Payments to Acquire Assets, Gross			239,120
Surety Bond [Member]
Payment of Bond Premiums	$ 116,279	$ 113,117	$ 118,944