May all your trips into the national parks be with the wind at your back, the sun overhead, and without mishaps. Sadly, we can't always ensure that accidents won't happen, and that's where some key First Aid items are nice to have on hand.
Along with sun block, bug repellent, blister applications, and an assortment of Band-aides and rolls of gauze, a nice product to have with you for worst-case situations is QuikClot Sport (MSRP $9.99/25g package and $14.99/50g package). This product, brought to you by the folks who make the Adventure Medical Kits, can stop bleeding from substantial wounds in a matter of minutes. According to the company, the product can reduce bleeding from anywhere between 10 and 30 minutes to fewer than 3 minutes. It does that through a hemostatic agent called Zeolite that is contained in a surgical sponge.
Now, this is not a new-fangled chemical concoction. It's been around for quite a while and has found use in detergents as a water softener, in insulated double glazed windows to prevent condensation, and even in oil refineries where it separates hydrocarbons. But in the field, when you've seriously cut yourself, this product hastens clotting by pulling the liquids out of your blood and so allowing the platelets to do their job and clot.
Use is simple: You place the gauze sponge over your wound and apply direct pressure for at least three minutes, or until bleeding stops. You won't be the first to use this product. It's already been carried into battle by U.S. military forces in Iraq and Afghanistan, where it reportedly has saved at least 150 lives, the company says.
If you're worried about staph infections or other bacteria out in the field, consider QuikClot Silver (MSRP $18.99/25g package and $20.99/50g package), which contains ionic silver. Adventure Medical also makes a smaller QuikClot product for use in halting nose bleeds, appropriately dubbed QuikClot Nosebleed.
Along with its clotting properties, QuikClot products are small and light, so they won't add much to either your pack's weight or your available storage space.