Breaking News (as on PR Newswire)

“Houston, Texas / PR Newswire – July 15, 2008 –Mainland Resources, Inc., a Nevada corporation (the “Company”) (MNLU-OTCBB, 5MN-Frankfurt) and Petrohawk Energy Corporation (“Petrohawk”) (NYSE: HK) have entered a binding agreement for the joint development of the Haynesville Shale on Mainland Resources’ properties (“the Leases”) in De Soto Parish, Louisiana effective July 14, 2008.

Mainland Resources, Inc. holds interest in approximately 2,695 net acres which form part of the East Holly Field in De Soto Parish, northwest Louisiana.

Under the terms of the Agreement, Petrohawk agrees to pay 100% of the costs of development associated with the first well drilled below the Cotton Valley Formation, including drilling, completing and fracture stimulating, as well as costs up to and including pipeline connection. Petrohawk also agrees to pay 80% of all costs of the second well drilled on the Leases below the base of the Cotton Valley and Mainland agrees to pay 20% of the costs. For the third and all subsequent wells drilled on the Leases below the base of the Cotton Valley Formation, Petrohawk will pay 60% and Mainland will pay 40%.

Mainland will transfer 60% of its De Soto Parish leases to Petrohawk at closing, but only as the Leases relate to all depths below the base of the Cotton Valley Formation, and specifically the Haynesville Shale. Petrohawk agrees to gather and market Mainland’s production from above the base of the Cotton Valley Formation, pursuant to a mutually acceptable agreement.

Mainland Resources President Mike Newport states, “The opportunity to work with Petrohawk Energy Corporation to jointly develop the Haynesville Shale on our properties changes the complexion of our entire company going forward. Petrohawk has built considerable expertise in the Haynesville and they bring major financial and operational resources that would speed up our Haynesville development in a very big way.”

“This arrangement allows Mainland to continue development on our De Soto Parish leases focusing on upper levels in the Cotton Valley and Hosston formations that we believe could also prove very productive,” says Newport.

Petrohawk (or its affiliate) will be designated Operator on all development. The first well under this agreement between Mainland and Petrohawk is anticipated to be spudded before August 31, 2008.

The Agreement is subject to customary due diligence to be carried out by Petrohawk. The companies expect to close the transaction no later than July 31, 2008.”