Its easy to spot where one lives in the Columbia Basin if you know what to look for. Russian Olive trees with the bark eaten off the branches. Ive seen them high up in these trees munching away. Also, dirt paths that have a swept look, like someone took a broom and swept it back n forth as they walked backwards down the trail. I also found a porcupine den built in a little cave in the base of a basalt cliff in the Potholes area near a water source. I bent over and looked inside. He was 10 feet in at the back, his little eyes staring back at me.

I haven't noticed to look in awhile, but when driving down Hwy 240 through Kennewick along Columbia park, look toward the river and the Russian Olive trees that grow amongst where the old campground used to be at the west end of the park. A lot of these trees have noticeable areas where the bark has been eaten off.
Interesting
https://www.mspca.org/animal_protection/about-porcupines/...Porcupines are primarily nocturnal animals who rest during the day in hollow trees and logs, underground burrows or in crevices found in rocky areas. They are most commonly found in coniferous or evergreen forests but have also been found in deciduous woodlands and among Creosote in North American deserts.
Porcupines are strict herbivores and virtually all species of trees found within a porcupine’s range are eaten. During warm months, porcupines eat leaves, buds, nuts, fruit, twigs, and green plants. During the winter, they chew through the outer tree bark to eat the tissue-like inner bark. Porcupines have been known to strip or “girdle” tree bark from both the trunk and upper limbs with their two front teeth, which can sometimes kill the tree...
...Due to a diet low in sodium, porcupines may try to satisfy their dietary need for salt by chewing on wooden structures, tools, and other materials used in outdoor work or recreation. They are attracted to almost any object that has been handled by humans because of the salt found in human sweat. Porcupines are also attracted to the glue used to bond plywood on wooden structures. Car tires and hoses may also be chewed on for their mineral content or road salt coating...