Income Tax - Schedule of Net Deferred Tax Asset (Details) - USD ($)	Apr. 30, 2019	Apr. 30, 2018
Income Tax Disclosure [Abstract]
Net operating loss carryover	$ 3,777,000	$ 1,905,000
Stock-based compensation	1,753,000	1,580,000
Capitalized exploration costs	341,000	163,145
Accrued remediation costs	3,000
Alternative minimum tax credit carryover	438,000	438,000
Subtotal	6,312,000	4,086,145
Less: valuation allowance	(6,312,000)	(3,648,000)
Net deferred tax asset		$ 438,145