Rising Marcellus gas production is making a mark on U.S. gas supply.

In fact, the sharp ramp in Marcellus shale gas production during the last year has become a key factor in the continuing expansion of U.S. onshore natural gas supply.

Domestically, the gas production surge has crippled market economics as an over-supplied market heads into the winter of 2011-12 with near record storage. Near month gas prices are currently below $3.66 per Mcf while the 12-month Henry Hub strip is now $3.76 per Mcf, down 19% from the beginning ...