Little Tamarack Mountain (W7O/NE-137) makes a nice activation destination in north-central Oregon as it's located in the Umatilla NF near a Forest Service rental cabin/lookout with two other summits nearby, including Ng Knob-4820 (W7O/NE-147) and Happy Jack Ridge (W7O/NE-139). I rented the cabin for two nights. Activated Little Tamarack on the first day, then bagged the other two summits the next.
W6PZA's blog
Little Tamarack... nice activation destination with rental cabin
Summit:
W7O/NE-137
Highland Flat - Ochoco NF
Summit:
W7O/CE-140
Highland Flat is located in the Ochoco National Forest, approx 15 miles north of Priveville. In April 2019 I completed a first-time activation of the summit which is suprising since there's very good forest road access up to near the activation zone. My activation was more challanging due to snow which resulted in a 4-mile snowshoe hike. But this is usually an easy 4-pointer and recommended for anyone visiting the Prineville area.