Besides repeating those worries whenever a new well is proposed, there's not much else the park service can do. Their actions, however, have left tribal officials simmering about outside interference by people who presume to know how to better develop Blackfeet land than the tribe itself.
"I don't go to your backyard and tell you what to do with it, right? I don't tell you how to drive your car, right?" said Ron Cross Guns, assistant director of the tribe's oil and gas department. "But everybody on the outside that comes to our reservation tells us what to do on our reservation."
The tension has existed since the drilling began in earnest more than three years ago, and it continues despite no significant oil production to date and a recent lull in exploration. There are dozens of wells drilled across the 1.5-million-acre reservation, with at least 18 within 20 miles of the park.
The park service is calling for a comprehensive, detailed study on the cumulative effects of all existing drilling to date, future drilling and what would happen if the wells start producing oil and gas.
Glacier Superintendent Chas Cartwright said he has no desire to stop reservation development, but wants to make sure it is done right.
"Our jobs as stewards of this place is to try to make sure it is a nice place 20, 30, 50, 100 years from now and that development, that would pose some serious challenges," said Cartwright, who is retiring Dec. 28.
His appeals have gone nowhere. Blackfeet oil and gas director Grinnell Day Chief said the tribe completes a well-by-well environmental assessment as required under the National Environmental Policy Act, and each assessment is approved by the federal Bureau of Indian Affairs.
"We're not required to respond to" Glacier officials, Day Chief said. "When you try to satisfy everybody you may as well stop developing your minerals. You can't satisfy everybody."
The Blackfeet point out that oil wells have been drilled for more than a century in Glacier's shadow. Two oil fields, one on the opposite side of the reservation from the park and the other near the Canadian border, were developed in the 1930s, but production has been waning for decades.
With the success of hydraulic fracturing in opening oil development 450 miles away in North Dakota's Bakken basin, exploration companies have given the Blackfeet reservation another look.
The reservation doesn't need another Bakken boom to help improve its 30 percent poverty rate and high unemployment, Cross Guns said. Just a fraction of that production would be enough to dramatically improve the economic situation for the more than 17,000 enrolled tribal members, he said.
Since March 2009, there have been 100 approvals or applications to drill wells on the reservation, according to data from the U.S. Bureau of Land Management. Not all of those applications have been approved, and not all that have been approved have been drilled.
Blackfeet Oil and Gas officials list 56 well locations on the reservation between January 2009 and April of this year. But there are recent signs the drilling hasn't yielded what the explorers had planned.
Two of the three main exploration companies, Newfield Production Co. and Rosetta Resources, have suspended or scaled back their exploration. The third, Anschutz Exploration Corp., said it is not actively drilling on the reservation, though it is still engaged in completion activities on recently drilled wells.
Tribal officials say if any of those companies drop out, there are others waiting to take their place.
Local groups have protested that hydraulic fracturing threatens to contaminate their land and water supplies, call the well pads an eyesore and worry about the increased truck traffic.
Angelika Harden-Norman, who is married to a tribal member and runs the Lodgepole Gallery and Teepee Village two miles outside of Browning, said the tribe provides residents little information. She started a Facebook page called Blackfeet Oil and posts whatever news she can find about reservation development.
"I'm fearful for tourist businesses. We have an oil well that is not even a mile away from here," she said. "Five miles down the road from us is the Flat Iron well. It is flaring, with a lot of smoke and a big flame. This is just a few miles away from Glacier park."
Cartwright holds out hope the park and the tribe can find common ground and work together on the development. He pointed to Theodore Roosevelt National Park, smack in the middle of North Dakota's Bakken boom, as a future he would like to avoid for Glacier.
"They are now surrounded by thousands of wells, 6,000 wells in the western third of North Dakota, and they're projecting 50,000 wells? I would say that that is not the kind of story that we'd like to see on the boundary of Glacier," he said.
Tribal officials insisted it knows best how to protect and develop their land, and Cross Guns pledged to push back against the opposition from outsiders and from within. "We put our hearts on the line for this land," he said. "Our heart is with our land. And we're not going to destroy it."