The UPR Rock Island 4-H well, located on the north plunge of Table Rock Field in Sweetwater County, Southwest Wyoming (S4-T19N-R97W), is the culmination of 5 years of cooperative government and industry research in the DOE Greater Green River Basin Production Improvement Project, a research partnership between DOE-FETC, Union Pacific Resources and GRI. The primary goal of this project is to explore technologies which could make production of the very large tight gas resources in southwestern Wyoming technically and economically feasible. The Union Pacific Resources Rock Island 4-H well (UPR RI 4-H) appears to be a successful attainment of this goal in the area north of Table Rock Field. Notable milestones achieved in the span of this project include: (1) The reduction of drilling time and expense for vertical wells deeper than 15,000? to less than half of the average time and cost encountered by industry during the last decade. This is critical to making deep, vertical or horizontal tight gas sandstone wells a viable option. (2) One of the deepest horizontal tight gas sandstone wells in the world (>14,950? TVD). (3) Greater than 95% recovery of three of the deepest horizontal cores in the world. (4) One of the highest unstimulated, sustained gas flow capacities (12-14 MMCFD) ever encountered in the tight-gas province of the Cretaceous Frontier Formation in Wyoming. (5) The initiation of ongoing plans for a horizontal drilling effort by industry to evaluate and exploit this previously unattainable resource.