The ice on most bodies of water in Washington County should be ready to support ice fishers. Iowa DNR Fisheries Biologist Chad Dolan says ice needs to be at least 4 inches thick to be considered safe to walk on. For snowmobiles and ATVs, ice thickness needs to be 5 inches. Dolan says, while we don’t see this around here, ice can begin supporting small vehicles at around 10 inches.  He recommends drilling test holes every few feet to ensure ice is safe.