BILLINGS, Mont. (AP) - The Trump administration is advancing plans to ease restrictions on oil and gas drilling and other activities on huge swaths of land in the American West that were put in place to protect an imperiled bird species.

MORE: Forest Service proposes changes to sage grouse protections

Land management plans released Thursday would allow more waivers for drilling to encroach into the bird's habitat.

That would reverse protections for greater sage grouse enacted in 2015, under President Barack Obama. Critics warn it could doom the birds.

The final Environmental Impact Statement and instructions for filing a written protest are available online.

Trump and Interior Secretary Ryan Zinke have vowed to open more public lands to drilling. Grouse protections have long been viewed by companies as an obstacle to development.

RELATED: Idaho inmates work to restore sage grouse habitat

The ground-dwelling birds are known for an elaborate mating ritual and range across portions of 11 states. Habitat loss and disease have decimated some populations.