Tight gas sand and gas shale (along with coalbed methane) are today among the most active new natural gas plays in the US. While labeled as unconventional and still considered by many to be speculative, unreliable resources, today's tight gas sand and gas shale situation is quite positive: &bull The majority of the largest'domestic natural gas fields, measured by gas production or reserves, are tight gas sands or gas shales. &bull The bulk of the giant gas discoveries of the 1990s have been from these two resource areas. &bull Large undeveloped tight gas sand and gas shale resources still exist, which will increase with technology. A measure of the growing importance of these gas resources is that tight gas sands and gas shales accounted for seven of the dozen largest US natural gas fields in terms of their 2001 production (Table 1). &bull Combined natural gas production from the top two fields, Blanco/Ignacio-Blanco and Basin (San Juan basin), has remained relatively steady for the past three years, with the decline in Basin field countered by an increase at Ignacio-Blanco. The production volumes in these two fields include tight gas as well as coalbed methane. &bull Jonah field (Green River basin) and Wattenberg field (DJ basin) show significant production increases, while the Giddings tight gas and chalk field in Texas has declined. &bull Fastest growing has been Newark East field in the heart of the Barnett shale gas play in North Texas, where gas production has nearly tripled in the past 2 years.