Representatives from the U.S. Army Corps of Engineers have started meeting with Big Bend area landowners about the prospect of border walls on their land. Landowners say they’re concerned about flood risks and the destruction of archeological sites.

U.S. Customs and Border Protection updated its map of planned border wall projects to add vehicle barriers and patrol roads to portions of Big Bend National Park on Tuesday. It’s not clear if the barriers would be temporary or permanent.

A West Texas river guide and church preservation group, along with a national advocacy group, argue in a lawsuit filed Thursday that the administration illegally bypassed a range of environmental protection laws as it plans a 175-mile stretch of border wall in the state’s Big Bend region.

Local officials are discussing how to move forward with a wall contractor’s use of a remote county road leading to the U.S.-Mexico border.