A very enjoyable way to hunt for arrowheads and other interesting keepsakes is to walk upland creeks and small rivers examining the gravels in the streambed.
Some of everything in a given watershed will end up in the gravels of the gullies and creeks, and with a little study and effort these places are excellent arrowhead hunting territory.
In most waterways, there is a rapidly eroding portion near the headwaters, an area of mixed washing and deposition in which there will be sand and gravel bars, and then a lower area where the sediments in the creek are too fine or muddy to reveal artifacts or fossils.
The upper portions where the rapid washing occurs will contain large artifacts and fossils that have recently dropped into the streambed. Finer materials and soil have been washed past these large pieces leaving them clean and marooned on a bare creekbed.
Medium sized artifacts and fossils will be swept down with rocks of similar size and weight until they settle on sand or gravel bars in the quieter areas of a drainage. To find these items you must look carefully, as they will be mixed with a large amount of waste rock. But if there are abundant artifacts in the area, some of them are sure to be present, and the cool, wet environment of the creekbed is a pleasant place to spend a morning looking through gravels.
Not every creek or small river is a good candidate for this type of search. Some areas are so rocky that even the upper beds of the creeks are too choked with refuse to be easily searchable. When this is the case, it is best to pick a different local landform and examine creeks in the new area. Small streams draining a mountain will often be rocky, but the streams draining the floodplain between ridges could be much less choked with rocks and pebbles. You may have to travel a few miles to find the right environment, but the right kind of creek or river is seldom very far.
Creeks and rivers are especially good places to hunt since the artifacts they contain are completely out of context and there is little chance of a valuable site being damaged by your presence. Most creek finds are isolated artifacts, but there are many creeks that contain so many arrowpoints that each trip will produce one or several, and often from widely different cultures or periods.