SALT LAKE CITY (AP) — A Utah company has cleared a final hurdle to develop the first commercial oil shale mine in the nation.

The Utah Division of Water Quality on Friday issued a groundwater permit to Red Leaf Resources, which plans to develop a shale mine on state land in the Uinta Basin in eastern Utah.

Utah media outlets are reporting that Red Leaf hopes to become the first company to extract oil in commercial amounts from shale that exists in abundance under Utah, Colorado and Wyoming.

Oil shale deposits in the three states represent a potentially huge, unconventional energy resource, but the trick is turning it into oil. Oil shale is rock that contains kerogen, which must be subjected to high heat before it produces liquid.

Red Leaf CEO Adolph Lechtenberger said in a statement that its initial, small-scale demonstration project "will produce more than 300,000 barrels of oil and prove our clean oil shale technology works on a large scale."

But environmentalists expressed skepticism, saying groundwater disturbance is just one of many environmental drawbacks posed by extraction of the Uinta Basin's rich oil shale and tar sands resources.