Hi Gabriel, thank you for the suggestions. Do you have any suggestions on where in the Cascades ?
There is no shortage of places. Nearly all of the Cascade range is part of one National or State forest, BLM, Fish and Wildlife, or something. Drive over Hwy 2, 12, 410 (Passes) and there are thousands of FS roads that exit the Hwy. Get some maps and just start exploring.
My favorite are is east of Yakima, Hwy 12 and 410. Bethel Ridge is a must see. Get a Butler Maps Washington Backcountry Discovery Route. It is a map of connecting roads that goes from the Oregon boarder (Bridge of the Gods) to the Nighthawk boarder crossing into Canada. I think it is 575 miles and is 95% dirt roads. This will take you through the heart of some of Washington's best areas. It mostly follows the Cascades on one side or the other and the views are spectacular. At least 100,000 places to camp along the way.
If I were you this is where I would start. Also, see all the green in the map below, that is where you want to go. It mostly all open and free for camping.
This 575-mile route thoroughly explores the Cascade Mountains beginning in Stevenson, WA and making it to the Canadian border at Night Hawk.
ridebdr.com