Denver (AP) -- The comment period ends Tuesday for the Army's request to bar mineral development at Fort Carson and a training area. The Bureau of Land Management is reviewing the Army's application to extend the withdrawal for 15 more years. About eight square miles of surface public lands and 221 square miles of subsurface federal minerals within the post and the Pinyon Canyon training site are currently off-limits for mineral leasing and development. The withdrawal is set to expire September 22nd unless it's extended. The request does not address whether the Pinon Canyon site should be expanded. The Army has periodically proposed adding land to Pinyon Canyon, but many area ranchers and residents oppose the idea.