Alton Bay is the village at the southern tip of Lake Winnipesaukee, in the town of Alton, NH. It sits at the head of a 4-mile cove where Routes 11 and 28A meet, about a mile north of Alton's town center, and it has its own ZIP code, 03810 (Wikipedia). It's known for the Alton Bay Seaplane Base and Ice Runway (FAA identifier B18), its bandstand on the water, and Mount Major just up Route 11.
Alton Bay is a village, not a town of its own. Property taxes, schools and zoning all come from the town of Alton, in Belknap County. This guide covers the bay and the village. For the lake as a whole (its depth, islands, boating rules and ice-out), see our Lake Winnipesaukee guide. To compare the eight lake towns, see our where to buy on Winnipesaukee guide.
Alton Bay at a glance
| Town and county | Alton, Belknap County |
| ZIP code | 03810 (the rest of Alton is 03809) |
| Location | Southern tip of Lake Winnipesaukee, at Routes 11 and 28A |
| Seaplane base and ice runway | FAA identifier B18, owned by the State of New Hampshire |
| Alton 2025 property tax rate | $13.50 per $1,000 of assessed value (NH DRA) |
| High school | Prospect Mountain High School, Alton |
| Nearby hike | Mount Major, 1,786 feet |
In this guide
- What is the Alton Bay ZIP code?
- Where is Alton Bay, New Hampshire?
- The Alton Bay ice runway and seaplane base
- The Alton Bay bandstand and the waterfront village
- Alton Bay Winter Carnival and fireworks
- Mount Major and the hills above the bay
- Alton taxes and schools
- Alton Bay NH real estate: waterfront vs village
- Frequently asked questions
What is the Alton Bay ZIP code?
The Alton Bay NH zip code is 03810. The rest of the town of Alton, including the town center, uses 03809. The split causes confusion on listings and delivery addresses, so it's worth knowing that 03810 is a postal area, not a separate tax district.
An "Alton Bay, NH" mailing address is taxed by the town of Alton at the town's single rate. The tax card, not the mailing address, tells you which town a property is in. That matters in this corner of the lake, where Alton borders Gilford, Wolfeboro and New Durham.
Where is Alton Bay, New Hampshire?
Alton Bay, New Hampshire is at the far southern end of Lake Winnipesaukee, where a long, narrow arm of the lake runs south for about 4 miles to the village. Route 11 follows the bay's west shore toward Gilford and Laconia. Route 28A follows the east side and joins Route 28 about four miles north of the village, toward Wolfeboro.
The village grew because of the water. In 1851 Alton Bay became the end of the Cochecho Railroad from Dover. The line became the Lake Shore Railroad in 1890, running west to Lakeport in Laconia, and passenger service ended in 1935. The steamer Mount Washington and her predecessors have called at Alton Bay since 1872, and the bay is still one of the cruise ship's ports. The Alton Bay Christian Conference Center began as the Second Advent Camp Meeting in 1863. It was incorporated in 1876 as the Alton Bay Camp Meeting Association, and it still runs retreats, summer camps and concerts.
The Alton Bay ice runway and seaplane base
The Alton Bay ice runway is a plowed landing strip on the frozen bay, open to small planes in winter once the ice is thick enough. It's part of the Alton Bay Seaplane Base and Ice Runway, a public airport owned by the State of New Hampshire and administered by NHDOT Aeronautics in Concord. Its FAA identifier is B18.
What the FAA airport record shows, per its data effective October 29, 2026 (AirNav, from FAA data):
- Waterway 1W/19W: a water lane 2,600 feet long and 100 feet wide. In winter, the ice is plowed to about 2,600 feet, and pilots check NOTAMs for ice runway conditions.
- Elevation: 504 feet, the lake's surface.
- Activated: February 1994.
- The bandstand rule: all seaplane takeoffs and landings must be north of the bandstand. The 1W threshold is about 100 feet northeast of the floating bandstand. Using 19W for takeoffs and landings is prohibited January through March.
- Radio: CTAF/UNICOM 122.8.
Is Alton Bay the only ice runway in the country?
Alton Bay is the only officially recognized seasonal ice runway in the contiguous United States, according to AOPA's February 2026 report. The Associated Press called it "the only FAA-approved ice runway in the lower 48 states" in a 2019 story carried by NHPR.
The Alton Bay ice runway opened for the 2026 season on January 31, once the ramp met the required 12 inches of ice, and AOPA counted 82 landings on opening day. The date changes every winter. A mild winter can delay the opening or cut the season short, so check current conditions before you drive up.
Watching the planes
The best place to watch planes on the Alton Bay ice runway is the shore by the bandstand and town docks. On a good weekend after the runway opens, small planes land on skis and wheels a short way out from the village. Watch from land: the plowed strip is an active runway, and ice on a lake this size is never uniform. The 12-inch minimum is for aircraft. For people on foot or in a bob-house, follow NH Fish and Game's ice-safety guidance and test the ice yourself.
In summer, B18 works as a seaplane base on the same water lane.
The Alton Bay bandstand and the waterfront village
The Alton Bay bandstand is a bandstand built over the water at the head of the bay. It's marked by New Hampshire Historical Highway Marker No. 288, "Alton Bay Water Bandstand." The FAA uses it as the reference point for every seaplane landing on the bay. Around it, the town docks, the waterfront walk and the shops along Route 11 make up the summer village.
The village is small and seasonal. In July and August, the docks and the walk along the head of the bay are the center of things. From November to April, most of the action moves out onto the ice for fishing and, when the runway opens, flying.
Alton Bay Winter Carnival and fireworks
Alton Bay Winter Carnival 2026
The Alton Bay Winter Carnival is a one-day winter event at Alton Bay, sponsored by the Alton Business Association. The 2026 carnival was scheduled for Sunday, February 15, 2026, from 10 a.m. to 2 p.m., per the Visit NH and NHPR event listings. It was free, with a shuttle bus from Alton Central School.
The 2027 Alton Bay Winter Carnival date had not been posted when we wrote this in November 2026. Confirm the date, schedule and parking with the Alton Business Association before you go, because the event depends on the weather.
Alton Bay fireworks 2026
The Alton Bay fireworks are the town's Independence Day show over the bay. In 2026, the Town of Alton set off its fireworks at the Alton Bay bandstand on Friday, July 3, at 9:20 p.m., with a rain date of Sunday, July 5 (Lakes Region events calendar). For the 2027 date, check with the Town of Alton in early summer, since the night moves with the calendar. Meredith, Wolfeboro and the other lake towns hold their own shows, which our Winnipesaukee guide lists.
Mount Major and the hills above the bay
Mount Major is the hike above Alton Bay and the classic Winnipesaukee summit. The summit is 1,786 feet (Wikipedia), and its open top looks straight up the lake. The blue-blazed Mount Major Trail climbs about 1.5 miles over open ledges from the lot on Route 11, up the west side of the bay. On a fall weekend, that lot is full early. Get there before 9.
Mount Major is also the best hike near Lake Winnipesaukee for a first visit. For more hikes and the White Mountains waterfalls an hour or so north, see our guide to the best hikes and waterfalls in the White Mountains.
Alton taxes and schools
Alton's 2025 property tax rate was $13.50 per $1,000 of assessed value, per the NH DRA's 2025 certified rates. It breaks down as:
| Part of the 2025 Alton rate | Per $1,000 |
|---|---|
| Municipal | $4.09 |
| County (Belknap) | $1.51 |
| Local education | $6.04 |
| State education | $1.86 |
| Total | $13.50 |
That was the highest of the eight Winnipesaukee towns in 2025 (Moultonborough was lowest at $5.33). Even so, it was below the simple average of about $17.10 across New Hampshire's 234 towns. On a $600,000 assessment, Alton's 2025 rate works out to $8,100 a year. Assessments often run below market value, so for a specific house, ask for the actual bill. Our NH property tax guide explains the four lines and how to compare towns fairly.
Schools. Alton's public schools are Alton Central School and Prospect Mountain High School. Prospect Mountain, at 242 Suncook Valley Road in Alton, opened in 2004 as the high school for Alton and Barnstead, run by a joint maintenance agreement (JMA) district of the two towns (Wikipedia). For SAU details, enrollment and programs, check the NH Department of Education school profiles.
Alton Bay NH real estate: waterfront vs village
Alton Bay NH real estate splits into three kinds of property, and they price and behave very differently.
Waterfront on the bay and the main lake. Waterfront homes run up both shores of the bay and out along Route 11 toward West Alton, and along Route 28A and the coves toward Wolfeboro. The bay is narrow and sheltered, which suits docks and small boats. Frontage out near the Broads has the bigger views and the bigger water. Any purchase within 250 feet of the lake now needs a septic evaluation under RSA 485-A:39, paid by the buyer (in effect since September 1, 2024). Docks and shoreline work fall under the state's shoreland rules, which our Lakes Region waterfront guide covers.
The village and close-in cottages. Near the head of the bay, older seasonal cottages sit close together on small lots, some with deeded or association water access rather than frontage. These cost less to buy than frontage. Before you budget, check year-round road access and plowing, winterization, and whether the water and septic are shared.
Off-water Alton. Alton is a large town, and most of its homes aren't on Winnipesaukee at all. Some sit on Merrymeeting Lake or the smaller ponds, and many are inland. That's why an Alton "waterfront" listing needs a second look: confirm which lake it's on. Rattlesnake Island, the highest island on Winnipesaukee, is also in Alton and is boat-access only.
Alton is generally the value side of Winnipesaukee: more house for the money than the north shore, with Route 11 running east to Rochester. For a side-by-side with the other lake towns, see our Wolfeboro guide and our Gilford buying guide.
When you're ready to tour, our buyer services page explains how we work with lake buyers. Our Lake Winnipesaukee homes page shows everything listed around the lake.
Frequently asked questions
What is Alton Bay, NH known for?
Alton Bay, NH is known for the Alton Bay Seaplane Base and Ice Runway (FAA identifier B18), which AOPA calls the only officially recognized seasonal ice runway in the contiguous United States. It's also known for its bandstand on the water, Mount Major just up Route 11, and its place at the southern tip of Lake Winnipesaukee. The steamer Mount Washington has called at Alton Bay since 1872.
What is the zip code for Alton Bay, NH?
The zip code for Alton Bay, NH is 03810. The rest of the town of Alton, including the town center, uses 03809. Both are in the town of Alton, which sets the property tax rate, so the ZIP code doesn't change the tax bill.
When does the Alton Bay ice runway open?
The Alton Bay ice runway opens only when the ice is thick enough, so the date changes every winter, and a mild winter can delay or shorten the season. In 2026 it opened on January 31, after the ramp reached the required 12 inches of ice, per AOPA. Pilots check NOTAMs for current ice runway conditions.
Is Alton Bay its own town?
No, Alton Bay is not its own town. Alton Bay is a village inside the town of Alton, in Belknap County. Alton sets the property tax rate ($13.50 per $1,000 of assessed value in 2025, per NH DRA), the zoning and the school district. Alton Bay just has its own post office and ZIP code, 03810.
When is the Alton Bay Winter Carnival?
The Alton Bay Winter Carnival 2026 was scheduled for Sunday, February 15, 2026, from 10 a.m. to 2 p.m., sponsored by the Alton Business Association, free, with a shuttle from Alton Central School. The 2027 date had not been posted as of November 2026, so confirm it with the Alton Business Association.
When are the Alton Bay fireworks?
The Alton Bay fireworks are the town's Independence Day show over the bay. In 2026, the Town of Alton set them off at the Alton Bay bandstand on Friday, July 3, at 9:20 p.m., with a July 5 rain date. Confirm the 2027 date with the Town of Alton.
What high school serves Alton Bay?
Prospect Mountain High School in Alton serves Alton Bay. Prospect Mountain opened in 2004 as the joint high school for the towns of Alton and Barnstead. Younger students in Alton attend Alton Central School.