Army Corps to cut hours at Lock 4 in Harrison Mary Ann Thomas Tuesday, May 21, 2019 5:28 p.m. | Tuesday, May 21, 2019 5:28 p.m. Go Ad-Free Today! Louis B. Ruediger | Tribune-Review A tug boat pushes a loaded barge in to place at Lock No.4 in Natrona Thursday. March 28, 2019. A tug boat pushes a loaded barge in to place at Lock No. 4 in Natrona on Thursday, March 28, 2019. Share this post: Facebook Twitter LinkedIn Reddit Email