- Ocean8
- Ocean City.1
- Ocean Isle Beach.1
- Ocean Springs, recently disturbed vacant lot just NW of corner of Hwy US 90 and Washington.1
- Oceana21
- Oceola Twp.1
- Ochoco National Forest, Ochoco Summit Campground.1
- Ochoco National Forest; Paulina Ranger District; unnamed tributary of Procupine Creek1
- Oconee13
- Oconto3
- Ocotito; Colotlipa; 9 mi SE Colotlipa2
- Ocqueoc Falls on PI 638 SE of Millersburg, Bismark T.S.1
- Ocqueoc Lake.1
- Ocueoc Falls on PI 638 SE of Millersburg, Bismark T.S.1
- Ocuilan1
- Ocurague; Ocurahui; Sierra Surotato3
- Odell Lake co, along highway 58.1
- Of Roby Lake, ca. 9 mi. SW of Baldwin.1
- Of Siskowit Bay, Isle Royale.1
- Of the Methow Valley District of the Okanogan National Forest, in or near the Pasayten Wilderness. From Wenatchee, about 110 miles north to Winthrop community. From Winthrop, about 12-14 miles northwest, at Thirty Mile Fire helibase.1