MINERAL PROPERTY INTEREST AND DEFERRED DEVELOPMENT COSTS (Detail) - Development Expenses - USD ($)	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Extractive Industries [Abstract]
Balance at April 30, 2018	$ 1,892,410	$ 1,145,906
Engineering and consulting		177,820
Metallurgy		263,056
Permitting and environmental		17,684
Interest on Promissory Notes		207,266
Other direct costs		80,678
Total		746,504
Balance at April 30, 2019 and 2020	$ 1,892,410	$ 1,892,410