Suggested Citation: Kerr, Andy. 2000. Oregon Desert Guide: 70 Hikes. Seattle: The Mountaineers Books. p. 38.
Though properly near the end, this is important. This author, at least, rarely defecates the first few days out. When finally moved by the moment, it is into a shallow (4 to 6 inches) trench dug with a boot heel or a stick (why buy and carry a trowel for the purpose?), located if possible in an area of good sunlight (heats the soil and accelerates the decomposition process). Into the trench also goes the toilet paper and then the dirt kicked back into the trench. Some advocate burning said paper, but it does decompose, and more than one unintended wildfire has resulted from such. (A female friend highly recommends sagebrush in lieu of paper for No. 1—make sure no insects are along for the ride—but this author cannot testify to it.)
In heavily defecated areas or river corridors, coyotes (like domestic canines) will dig up and consume your deposited delectable delight, leaving the toilet paper visible. Portapotties are now required on river trips.
A resealable plastic bag (one inside the other if you don't trust technology) can be used to pack out toilet paper and those uniquely feminine items.
For more on the subject (and there actually is quite a bit more), see Recommended Reading.