Water
Pure drinking water you must have, it is of vital importance, so be sure to pitch your camp within near walking distance of a good spring, a securely covered well, or other supply of pure water.
Henry David Thoreau's method of obtaining clear water from a pond whose surface was covered with leaves, etc., was to push his pail, without tipping it in the least, straight down under the water until the top edge was below the surface several inches, then quickly lift it out; in doing this the overflow would carry off all leaves and twigs, leaving the remaining water in the pail clear and good. But you must first be sure that the pond contains pure water under the floating débris.
Always be cautious about drinking water from rivers, streams, ponds, and lakes though they may appear ever so clear and tempting, for the purity is by no means assured, and to drink from these sources may cause serious illness. Unless you are absolutely sure that water is free from impurities, boil it; then it will be safe to use for drinking and cooking.
Next in importance to good water is good fire-wood and woodsy material for shelters and beds. Bear this in mind when deciding upon the site for your camp.