🌤 Weather at Fort O’Brien State Historic Site by season
| Spring | Summer | Fall | Winter |
|---|---|---|---|
| 22–61 °F | 51–76 °F | 30–69 °F | 9–35 °F |
Each range runs from the coldest monthly average low to the warmest monthly average high in that season (1991-2020 climate normals), measured at Jonesboro, 13 mi away, elevation 194 ft. Conditions at the park can differ from the station, especially where elevation differs — check a forecast before you go.
🏆 First Naval Battle of Revolution — Site of the FIRST naval battle of the American Revolution — June 12, 1775 (before Bunker Hill!)
Fort O’Brien State Historic Site in Machiasport preserves the earthworks of Fort O’Brien — site of the first naval battle of the American Revolution! On June 12, 1775 (five days before Bunker Hill!), Machias patriots captured the British armed schooner HMS Margaretta in the “Lexington of the Sea.” Local lumbermen, armed with pitchforks and muskets, rowed out in lumber boats and overwhelmed the British crew. The battle proved that colonial resistance wasn’t limited to Massachusetts — even the remotest Maine coast was ready to fight.
Visitor Information
| Detail | Information |
|---|---|
| Location | Machiasport, Washington County, ME |
| Entry Fee | Free |
| Battle | FIRST naval battle — June 12, 1775! |
| Nickname | “Lexington of the Sea”! |
Frequently Asked Questions
What was the “Lexington of the Sea”?
Five days before Bunker Hill, Machias lumbermen attacked HMS Margaretta with pitchforks! The captured vessel became one of the first ships in what would become the Continental Navy. Machias patriots proved that Revolution wasn’t just a Boston phenomenon.
About Fort O’Brien
Fort O’Brien State Historic Site in Machiasport preserves the remains of fortifications overlooking Machias Bay — site of the first naval battle of the American Revolution (June 1775), even before Bunker Hill. Local patriots captured the British armed schooner HMS Margaretta in a daring raid. The earthworks of the 1775 fort and later War of 1812 defenses remain visible.
Things to Do
Exploring the historic fort earthworks, learning about the first naval battle of the Revolution, enjoying spectacular Machias Bay views, and visiting the nearby Machias Historical Society. One of Maine’s most historically significant but least-visited sites.
Make it a road trip: Pair a visit with Roques Bluff State Park (a short drive away) or Roque Bluffs State Park (a short drive away).
⚓ Visit Fort O’Brien SHS
FIRST naval battle of the Revolution — “Lexington of the Sea” June 12, 1775!
Wildlife & Nature
Fort O’Brien SHS — site of the first naval battle of the American Revolution (June 12, 1775) — the Battle of Machias, where local patriots captured the British armed schooner HMS Margaretta. The site’s Machias River, coast, and forest support bald eagles, ospreys, and harbor seals.
Nearby Attractions
Machiasport — adjacent. Machias — 5 miles upstream — “Blueberry Capital of the World”. Bold Coast — 15 miles east.
🐾 Dogs & Pets at Fort O’Brien State Historic Site
- Pets allowed? statewide rule
- Pets are allowed at most Maine state parks year-round, including trails, but must be leashed, under the handler's physical control and never left unattended.
- Leash rule statewide rule
- Leash not exceeding 4 feet, under the physical control of the handler
- Beaches & swim areas statewide rule
- Pets are not allowed on state park beaches April 1 through September 30; leashed pets are welcome on beaches October 1 through March 31
- Statewide exceptions statewide rule
- No pets allowed at Sebago Lake State Park campground; park staff may assign pet owners to less congested camping areas
Are dogs allowed at Fort O’Brien State Historic Site?
Pets are allowed at most Maine state parks year-round, including trails, but must be leashed, under the handler's physical control and never left unattended. Individual parks can post stricter rules — check signage on arrival.
Rules verified July 2026 via maine.gov. More: Maine state parks guide · Dog rules in all 50 states compared
