Note 1 - Organization and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Schedule of Asset Retirement Obligations [Table Text Block]

	2018			2017
Beginning of period	$	17,366,270		$	17,124,630
Liabilities incurred		-			877
Liabilities settled		(676,425	)		(114,364	)
Accretion expense		313,641			355,127
End of period	$	17,003,486		$	17,366,270