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History · Mongaup Valley

Mongaup Valley’s post office opened in 1848, and 14% of its homes were built before 1940

Below: 2 old photos and papers from 1875 on.

1848first post office
0on the National Register
14%homes built before 1940
2old photos & papers
Add an old photoShare a memory
From Mongaup Valley’s archive · credits on each photo
Quick answers

How Mongaup Valley began

When was Mongaup Valley founded?

1848

The Mongaup Valley post office opened in 1848, the earliest record of the town by name.

2020 census: 236178 years
Founding year: the first Mongaup Valley post office (Blevins & Helbock, CC0).

What stands out about Mongaup Valley’s past

Read from the archive, the National Register and the record. The page puts what stands out first.

A history waiting to be writtenOnly 2 old photos are in the public archives. The rest are in attics and albums.Deep rootsA post office since 1848: 178 years of Mongaup Valley.Old housesHalf of Mongaup Valley’s homes were built before 1961.
★ What stands out · Help out

Start Mongaup Valley’s collection

The first neighbors to add old photos shape how Mongaup Valley’s history is told.

Decades since 1900 with photos
00s10s20s30s40s50s60s70s80s90s
1 of 10 decades. The empty ones are waiting for someone’s album.
Retake an old viewMongaup Valley NY Presby PHS801: stand where they stood+15Share a family photoSign in to add one+10
The story so far

Mongaup Valley, in brief

Wikipedia doesn’t have a history of Mongaup Valley yet. The photos, dates and memories neighbors add here are how it gets written.

Mongaup Valley is a hamlet (and census-designated place) in the Town of Bethel, Sullivan County, New York, United States. As of the 2020 census, Mongaup Valley had a population of 236. The community is located along New York State Route 17B 5 miles (8.0 km) west of Monticello, and along the Mongaup River. Mongaup Valley has a post office with ZIP code 12762, which opened on June 22, 1848.

Its first post office opened in 1848.

Intro from Wikipedia. Population: U.S. Census Bureau.

By decade

Mongaup Valley, decade by decade

2 decades in the archive, from the 1870s to the 1920s. Scroll each row; tap a photo for its story.

1870s1 item
County atlas of Sullivan, New York1875County atlas of Sullivan, New YorkMap
1920s1 item
Mongaup Valley NY Presby PHS8011923Mongaup Valley NY Presby PHS801
1930s–1990snothing yet
Nothing in the archives for these yearsWeddings on Main Street, storms, parades, school pictures, the old store. If it’s in your family album, it belongs here.
Add from your album
Today4 recent
D&H Mongaup 2018-11-01 5852018D&H Mongaup 2018-11-01 585D&H Mongaup 2018-11-01 5762018D&H Mongaup 2018-11-01 576D&H Mongaup 2018-11-01 5752018D&H Mongaup 2018-11-01 575Battle of Minisink 2018-11-01 6432018Battle of Minisink 2018-11-01 643
Then & now

Stand where they stood

No then-and-now pairs yet. Take a photo from the same spot as an old one and they appear here side by side.

Mongaup Valley NY Presby PHS801
Retake this viewMongaup Valley NY Presby PHS801, 1923

Find the spot, match the angle, and add your photo. It becomes the first then-and-now pair on Mongaup Valley’s page.

Retake this view · +15
Famous people

Famous people close to Mongaup Valley

Nobody well known was born in Mongaup Valley itself, so here are the best known from just nearby.

See all →
Frederick CookAmerican explorer · b. 1865
Gavin DeGrawAmerican singer · b. 1977
Queen HarrisonAmerican hurdler and sprinter · b. 1988
Randall BatinkoffAmerican actor · b. 1968
Stanley FinchFirst director of the FBI · b. 1872
Z
Zoe LeonardAmerican photographer · b. 1961
Stories next door

History across the town line

Each neighbor’s History grade, on the same three inputs.

SmallwoodIts storynot graded: under 1,000 residents or part of its townBethel2 historic placesB+Thompson6 historic placesA−

Questions about Mongaup Valley’s history

What year was Mongaup Valley founded?

The Mongaup Valley post office opened in 1848, the earliest record of the town by name (U.S. post office records).

Memory lane

What the archives can’t tell you, neighbors can.

Town Square →
Start a conversation
Sources

Where this page comes from

Founding dates: Wikidata, Wikipedia, the U.S. post office records of Blevins & Helbock (CC0) and the Census. Homes by year built: Census ACS 2020–24. National Register of Historic Places: National Park Service (list of May 22, 2026). Old photos, postcards and papers: Wikimedia Commons, the Library of Congress and other public archives, credited on each item’s page. Maps: U.S. Geological Survey historical topographic maps (via Esri) and Sanborn fire-insurance maps (Library of Congress). History text and census tables: Wikipedia (CC BY-SA 4.0). Places that used to be: USGS Geographic Names Information System (2021). How TownRatings grades history →

From Wikimedia Commons (6). Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.