Plummeting oil and natural gas prices mean lower royalty payments to enrolled members of the Eastern Shoshone and Northern Arapaho tribes. December payments to each enrolled Eastern Shoshone is $150, down from $300. The Northern Arapaho per capita was reduced from $150 to $75, Wind River Agency Superintendent Perry Baker said. 'Royalty collections from oil and gas production has declined approximately 72 percent from December of 2000 through October of 2001,'' a BIA news release said. Natural gas prices have declined even more. In December 2000, natural gas produced on the reservation was selling for around $9 per thousand cubic feet. Today, the price is about $1 per mcf, not counting transportation and other costs associated with production and marketing which would further reduce the price for royalty purposes. Additionally, increased gas production from other areas of the state produced a surplus of natural gas and created an imbalance between demand and supply. Royalty checks in the future could be reduced even more if prices continue to fall, the BIA release said. A problem with a bar code reader delayed the delivery of some per capita checks on the Wind River Reservation, the Wind River Agency said. Some of the missing checks have been received.