Quarterly report pursuant to Section 13 or 15(d)

Balance Sheets (Current Period Unaudited) (Parentheticals)

v3.5.0.2
Balance Sheets (Current Period Unaudited) (Parentheticals)
Jun. 30, 2016
a
$ / shares
shares
Dec. 31, 2015
a
$ / shares
shares
Royalty Interests in Acres 1_16 [Member]    
Nonparticipating perpetual royalty interest, acres 373,777 373,777
Royalty Interests in Acres 1_128 [Member]    
Nonparticipating perpetual royalty interest, acres 85,414 85,414
Real estate acquired, acres 10,065 10,065
Land (surface rights), acres 878,259 878,268
Certificates of proprietary interest, par value (in dollars per share) | $ / shares $ 100 $ 100
Certificates of proprietary interest, outstanding (in shares) | shares 0 0
Sub-share certificates of proprietary interest, par value (in dollars per share) | $ / shares $ 0.0333 $ 0.0333
Sub-share certificates of proprietary interest, outstanding (in shares) | shares 8,014,633 8,118,064