Colorado parks commissioners on Thursday tentatively endorsed a plan to open a state park to oil and gas drilling.

The proposal, first raised last year, would let an energy company drill in St. Vrain State Park — a newly developed wetlands area north of Denver that is home to white pelicans, blue herons and bald eagles.

Drilling for oil could begin next year.

“If we can do this with fairly limited environmental impact, I don’t see the real downside,” said Parks and Wildlife Commission chairman Tim Glenn, echoing views of the other commissioners. “Given the issue of where we are financially, . . . we have to look at virtually everything” that could increase revenues.