While ice on bodies of water in Washington County should be able to support anglers, it never hurts to double check ice thickness. Iowa DNR Fisheries Biologist Chad Dolan says ice needs to be at least 4 inches thick to walk on. For snowmobiles and ATVs, ice thickness needs to be 5 inches. Dolan says we don’t see this around here, but ice can begin supporting small vehicles at around 10 inches. He recommends drilling test holes every few feet to ensure ice is thick enough, and adds that no ice should be considered safe.