It goes without saying that public schools are absolutely everywhere in this nation. Often three or more per county, rarely less.
These institutions are not often known for having some magical source of supplies for survival. However schools across the nation have a very important task to complete once a day. Feed the kids. While the majority of the food may be frozen and gone bad after a SHTF situation there will still be plenty of foods suitable for consumption.
This includes things like cereal, powdered mashed potatoes, cookies, canned fruits and vegetables, as well as the potential to find sports drinks or powdered juices. These drinks can be a valuable source of sugar, sodium, potassium, etc.
Another advantage is an abundance of first aid kits. Most schools will keep one per classroom, as well as a stocked Nurses’ office. These kits are very basic, but can provide important wound cleansing agents, bandages, gauze, and potentially burn kits. Burn kits are especially prevalent in chemistry classrooms. A working nurses office could very well be cleaned out, but if not there can be a wide variety of medical gear present.
The last advantage is the janitor’s closet. These closets are not just full of cleaning supplies, but many useful items. Yard tools like shovels, machetes, rakes, and other valuable goods are nearly always stored in certain areas of the school. Other potential tools can include small hand tools, bolt cutters, and even some power tools.