SEGMENTED INFORMATION (Details 1) - USD ($)	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Costs and Expenses:
Mineral property expenditures	$ 4,552,151	$ 4,120,388	$ 4,061,159
General and administrative	11,407,206	10,241,681	9,297,746
Depreciation, amortization and accretion	354,624	497,728	875,724
Impairment loss on mineral properties	0	297,942	97,114
Inventory write-down	0	60,694	0
Total Cost and Expenses	16,313,981	15,218,433	14,331,743
Loss from operations	(16,313,981)	(15,218,433)	(14,331,743)
Other income (expenses)	(2,220,164)	(2,786,978)	(3,030,368)
Loss before income taxes	(18,534,145)	(18,005,411)	(17,362,111)
United States Texas [Member]
Costs and Expenses:
Mineral property expenditures	2,381,993	2,450,834	2,733,007
General and administrative	7,055,370	7,053,270	6,447,801
Depreciation, amortization and accretion	325,567	487,288	857,966
Impairment loss on mineral properties	0	185,942	0
Inventory write-down	0	60,694	0
Total Cost and Expenses	9,762,930	10,238,028	10,038,774
Loss from operations	(9,762,930)	(10,238,028)	(10,038,774)
Other income (expenses)	(2,630,691)	(2,772,617)	(3,012,281)
Loss before income taxes	(12,393,621)	(13,010,645)	(13,051,055)
United States Arizona [Member]
Costs and Expenses:
Mineral property expenditures	100,296	101,628	236,717
General and administrative	13,877	33,761	205,591
Depreciation, amortization and accretion	0	0	0
Impairment loss on mineral properties	0	8,334	0
Inventory write-down	0	0	0
Total Cost and Expenses	114,173	143,723	442,308
Loss from operations	(114,173)	(143,723)	(442,308)
Other income (expenses)	(18,914)	(18,914)	(18,965)
Loss before income taxes	(133,087)	(162,637)	(461,273)
United States Wyoming [Member]
Costs and Expenses:
Mineral property expenditures	1,282,164	0	0
General and administrative	581,277	0	0
Depreciation, amortization and accretion	12,847	0	0
Impairment loss on mineral properties	0	0	0
Inventory write-down	0	0	0
Total Cost and Expenses	1,876,288	0	0
Loss from operations	(1,876,288)	0	0
Other income (expenses)	1,541	0	0
Loss before income taxes	(1,874,747)	0	0
United States Other States [Member]
Costs and Expenses:
Mineral property expenditures	67,550	70,588	133,518
General and administrative	10,931	3,933	2,724
Depreciation, amortization and accretion	996	996	2,821
Impairment loss on mineral properties	0	103,666	97,114
Inventory write-down	0	0	0
Total Cost and Expenses	79,477	179,183	236,177
Loss from operations	(79,477)	(179,183)	(236,177)
Other income (expenses)	0	0	0
Loss before income taxes	(79,477)	(179,183)	(236,177)
Canada [Member]
Costs and Expenses:
Mineral property expenditures	0	0	0
General and administrative	3,467,934	3,063,839	2,636,514
Depreciation, amortization and accretion	11,599	8,088	8,142
Impairment loss on mineral properties	0	0	0
Inventory write-down	0	0	0
Total Cost and Expenses	3,479,533	3,071,927	2,644,656
Loss from operations	(3,479,533)	(3,071,927)	(2,644,656)
Other income (expenses)	423,657	636	850
Loss before income taxes	(3,055,876)	(3,071,291)	(2,643,806)
Paraguay [Member]
Costs and Expenses:
Mineral property expenditures	720,148	1,497,338	957,917
General and administrative	277,817	86,878	5,116
Depreciation, amortization and accretion	3,615	1,356	6,795
Impairment loss on mineral properties	0	0	0
Inventory write-down	0	0	0
Total Cost and Expenses	1,001,580	1,585,572	969,828
Loss from operations	(1,001,580)	(1,585,572)	(969,828)
Other income (expenses)	4,243	3,917	28
Loss before income taxes	$ (997,337)	$ (1,581,655)	$ (969,800)