Until January my sister's revenue distributor for Grady/Stephens Co. oil royalties was High Sierra. Small payments came every other month or so. In Feb. she received a new division order from Plains Marketing in Houston, which evidently owns HS's rights effective Jan 2012. Since then, not a single payment. When called, Plains says "no production reported yet by operator." Seems highly coincidental that production would cease just at the switchover from High Sierra to Plains. Anybody know about Plains--good experience or otherwise? Thanks for any guidance.