Note 5 - Share Capital (Tables)

9 Months Ended

Feb. 28, 2019

Notes Tables

Share-based Compensation, Stock Options, Activity [Table Text Block]

	Nine months ended February 28, 2019						Year ended May 31, 2018
	Number of Options			Weighted Average Exercise Price			Number of Options			Weighted Average Exercise Price
Balance, beginning of the period		9,861,900		$	0.85			8,846,900		$	0.87
Granted		4,520,000			2.06			1,840,000			0.77
Exercised		(4,036,900	)		(0.86	)		(256,660	)		(0.66	)
Forfeited		(30,000	)		(0.96	)		(568,340	)		(0.93	)
Balance, end of the period		10,315,000		$	1.38			9,861,900		$	0.85

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

	February 28, 2019						May 31, 2018
Expiry Date	Exercise Price		Number of Options		Exercisable at Period- End		Exercise Price		Number of Options		Exercisable at Year- End
September 19, 2017*	$	0.96		—		—	$	0.96		1,966,900		1,966,900
August 16, 2018*	$	0.76		—		—	$	0.76		2,095,000		2,095,000
September 8, 2019	$	1.40		1,250,000		1,250,000	$	1.40		1,250,000		1,250,000
September 9, 2020	$	0.46		620,000		620,000	$	0.46		625,000		625,000
November 13, 2020	$	0.49		1,000,000		1,000,000	$	0.49		1,000,000		1,000,000
September 15, 2021	$	0.91		1,085,000		1,085,000	$	0.91		1,085,000		722,610
July 31, 2022	$	0.77		1,840,000		612,720	$	0.77		1,840,000		—
November 19, 2023	$	2.06		4,520,000		—	$	—		—		—
				10,315,000		4,567,720				9,861,900		7,659,510

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

For the nine months ended Feburary 28,	2019			2018
Risk-free interest rate		2.28	%		1.65	%
Expected life of options (in years)		5			5
Annualized volatility		73.69	%		79.14	%
Dividend yield		0	%		0	%
Exercise price	$	2.06		$	0.77
Fair value per share	$	1.54		$	0.52

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

For the nine months ended Feburary 28,	2019		2018
Consulting fees	$	423,134	$	231,065
Exploration expenditures - Geological/geophysical		85,090		41,166
Investor relations		130,676		69,817
Professional fees		7,533		5,511
Wages and benefits		315,715		161,306
	$	962,148	$	508,865