Threemile Canyon Park is owned and operated by the U.S. Army Corps of Engineers, located at Exit 151 along I-84, about 12 miles west of Boardman, Oregon.
It is incorrectly named “Quesna County Park” on Google Maps.
You can park your RV here for 14 consecutive nights, all for free. The only amenities is a pit toilet, a boat ramp, and that’s about it. I didn’t even spot a garbage dumpster.
The closest sewer dump station is at the Boardman Marina RV Park, about 12 miles to the east. There’s a free RV dump station (with clean, drinking water) 66 miles to the east, at Arrowhead Travel Plaza, just east of Pendleton, OR, if you plan to head that way.
However, the other campers were respectful during our 7 night stay here. We didn’t hear any loud noises at night or during the day. When we stayed here, there several other RVers here, and at one point, there wasn’t an available campspot. There are no designated campsites here, you just park it where you can fit it.
A couple of campers had their generators going most of the day, and even into the night. Noise from the interstate was minimal. Meanwhile, Verizon 4G signal came in strong (5/5 bars).
There is an Indian treaty fishing camp located behind a chain-link fence. Only members of Columbia River indian tribes are allowed in. Do not go in!
A park ranger from the U.S. Army Corps of Engineers patrols every few days.
The biggest downside to staying at Threemile Canyon Park is there are tons of gnat flying about. Just as the afternoon sun makes it way down, the gnats come out in droves. Swarms of them are all over. Keep your doors shut at all times. It gets so bad, you just can’t handle sitting outside to watch the sunset. The winds can also blow pretty heavy, which is great for blowing the gnats away, however it still doesn’t make for sitting outside any pleasant.
The only store is a Love’s Travel Center located about five mile east on I-84.