Note 17 - Segmented Information - Operating Results by Geographic Segments (Details) - USD ($)	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Mineral Property Expenditures	$ 4,582,403	$ 4,487,537	$ 4,552,151
General and administrative	9,441,898	10,142,035	11,407,206
Depreciation, amortization and accretion	310,222	347,441	354,624
Loss from operations	(14,334,523)	(14,977,013)	(16,313,981)
Other income (expenses)	(281,544)	(2,190,148)	(2,220,164)
Loss before income taxes	(14,616,067)	(17,167,161)	(18,534,145)
United States Texas [Member]
Mineral Property Expenditures	3,165,898	3,072,855	2,381,993
General and administrative	6,982,684	6,619,855	7,055,370
Depreciation, amortization and accretion	273,687	314,599	325,567
Loss from operations	(10,422,269)	(10,007,309)	(9,762,930)
Other income (expenses)	(3,417,783)	(3,337,331)	(2,630,691)
Loss before income taxes	(13,840,052)	(13,344,640)	(12,393,621)
United States Arizona [Member]
Mineral Property Expenditures	104,191	112,724	100,296
General and administrative	13,717	14,040	13,877
Depreciation, amortization and accretion
Loss from operations	(117,908)	(126,764)	(114,173)
Other income (expenses)	(18,965)	(18,914)	(18,914)
Loss before income taxes	(136,873)	(145,678)	(133,087)
United States Wyoming [Member]
Mineral Property Expenditures	596,551	655,807	1,282,164
General and administrative	112,193	147,648	581,277
Depreciation, amortization and accretion	14,876	14,876	12,847
Loss from operations	(723,620)	(818,331)	(1,876,288)
Other income (expenses)	2,095	2,284	1,541
Loss before income taxes	(721,525)	(816,047)	(1,874,747)
United States Other States [Member]
Mineral Property Expenditures	69,523	69,910	67,550
General and administrative	2,277	3,557	10,931
Depreciation, amortization and accretion	850	996	996
Loss from operations	(72,650)	(74,463)	(79,477)
Other income (expenses)		1,578,864
Loss before income taxes	(72,650)	1,504,401	(79,477)
CANADA
Mineral Property Expenditures		16,078
General and administrative	2,272,138	3,165,883	3,467,934
Depreciation, amortization and accretion	11,959	11,666	11,599
Loss from operations	(2,284,097)	(3,193,627)	(3,479,533)
Other income (expenses)	3,147,724	(432,598)	423,657
Loss before income taxes	863,627	(3,626,225)	(3,055,876)
PARAGUAY
Mineral Property Expenditures	646,240	560,163	720,148
General and administrative	58,889	191,052	277,817
Depreciation, amortization and accretion	8,850	5,304	3,615
Loss from operations	(713,979)	(756,519)	(1,001,580)
Other income (expenses)	5,385	17,547	4,243
Loss before income taxes	$ (708,594)	$ (738,972)	$ (997,337)