| Official Name: | Green Mountain, Iowa |
| Settlement Type: | Census-designated place |
| Pushpin Map: | Iowa#USA |
| Pushpin Label: | Green Mountain |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Marshall |
| Established Title: | Established |
| Established Date: | 1883 |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 1.78 |
| Area Land Km2: | 1.78 |
| Area Water Km2: | 0.00 |
| Area Total Sq Mi: | 0.69 |
| Area Land Sq Mi: | 0.69 |
| Area Water Sq Mi: | 0.00 |
| Population As Of: | 2020 |
| Population Footnotes: | [2] |
| Population Total: | 113 |
| Population Density Km2: | 63.62 |
| Population Density Sq Mi: | 164.72 |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 991 |
| Coordinates: | 42.1017°N -92.8206°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 50632 |
| Area Code: | 641 |
| Blank Name: | FIPS code |
| Blank Info: | 19-32925 |
| Blank1 Name: | GNIS feature ID |
Green Mountain is a rural unincorporated community and census-designated place (CDP) in Marshall County, Iowa, United States. It is located in Marion Township. As of the 2020 census the population of Green Mountain was 113.[2]
As early as 1856, a few settlers from Vermont settled about a mile north of the present-day community; they named their community after their home in Vermont. The present-day town of Green Mountain, south of the original townsite, was established in 1883, platted by the Iowa Construction Company. The town was built adjacent to the Chicago Great Western Railroad.[3]
The Green Mountain Congregational Church, one of the first in the county, was built in Green Mountain, along with a grain elevator and a few businesses; a savings bank was constructed in 1907.[3] The population of the community was 41 in 1902.[4]
Green Mountain, Iowa, was the site of the Green Mountain train wreck. The wreck is known as the worst ever in Iowa history, as 52 people were killed in the accident on March 21, 1910.
In 1925, Green Mountain's population was 106.[5]
Green Mountain is in northeastern Marshall County, 7miles northeast of Marshalltown, the county seat. According to the U.S. Census Bureau, the Green Mountain CDP has an area of 0.69sqmi, all land.[1] The headwaters of Nickolson Creek run through the west side of the community, flowing south to join Rock Creek, which in turn joins the Iowa River east of Marshalltown.
The GMG Community School District serves the community. The district was established on July 1, 1992, by the merger of the Garwin and Green Mountain school districts.[6]