Great Sand Dunes National Park, in the foreground, sits below the west side of the Sangre de Cristo Mountains in the San Luis Valley. The Bureau of Land Management is considering leasing land for oil and gas drilling on the eastern side of the mountains.

(Nathaniel Minor/CPR News)

The Bureau of Land Management says it's received 3,000 comments on a controversial plan to lease federal land for oil and gas drilling in southern Colorado, and an agency spokesman said Friday that many commenters were under the mistaken impression that the drilling would be in the Great Sand Dunes National Park.

The 11 parcels comprising 18,000 acres south of Westcliffe are on the eastern side of the Sangre de Cristo mountains from the park boundary.

"The narrative that's out there that we're leasing Great Sand Dunes National Park or the notion that there would be a drill rig next to the actual sand dunes. That's not what's proposed. There is no proposal to offer any leases in the San Luis Valley,” said BLM spokesman Steven Hall.

Environmental groups agree with Hall, though they caution that effects of the drilling would still be visible from parts of the park.

"We are working to make very clear that this is near the park, it's on the eastern side of the park, but the effects could affect the dark night skies and also the air quality of the park.,” said Kimberly Pope of the Sierra Club. "One of the more popular trails that goes through Medano Pass starts right where one of the leases is. So people that take that trail through the park over the mountain range would definitely be impacted."

The Sierra Club has mapped the location of the leases and published the data here.

Anna Lee Vargas from Conejos Clean Water says the effects could still be felt in the valley.

"If you are a native of the San Luis Valley you know that winds blow from east to west,” She said. That means there’s “fear and concern for our air quality."

The BLM will review the comments and expects to issue a decision on the drilling leases this summer.

"There certainly could be an impact to the visitor's experience if they were on the far eastern edge of the park, up at the summit” of the mountains to the east of the dunes,” Hall said. “Then they might be able to see some oil and gas development."