When was Montgomery County founded?

Montgomery County was founded in 1837, formed from Liberty County, Washington County and Austin County, and named after Montgomery, Texas.

What is the county seat of Montgomery County?

The county seat of Montgomery County is Conroe.

Is there an online parcel map for Montgomery County?

Yes. A public source publishes a parcel map of 321,933 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Montgomery County's boundary or name changed?

Montgomery County was created in 1837 from Liberty County, Washington County and Austin County. Since then the Atlas of Historical County Boundaries records 8 later changes, chiefly involving Hamilton County, Madison County and San Jacinto County.

Is my lot in a flood zone?

We do not have flood maps for Montgomery County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

County · code 48339

Montgomery CountyTexas

Montgomery County is a county in Texas with its seat in Conroe, formed on December 14, 1837.

Founded1837
County seatConroe
Named forMontgomery, Texas
Land area1,042 sq mi + 35 sq mi water
Population620,443 2020 Census
Parcels mapped321,933 checked 15 October 2026

Open the free map Click any parcel in Montgomery County: acreage, parcel id, address and who publishes the map. No sign-in.

Updated 20 October 2026

Census outline · seat marked

History

Formed in 1837 from Liberty County, Washington County and Austin County

An old deed may name a county that no longer exists, or a boundary that has since moved.

The Republic of Texas created Montgomery County from Liberty, Washington, and a small part of Austin. Montgomery gained territory from Harris in 1840, then lost and regained land through the creation and elimination of judicial counties over the next two years. When Texas became a state in 1845, Montgomery became a county in the new state and soon after lost territory to the creation of Grimes and Walker counties in 1846. San Jacinto County was created from Montgomery in 1870.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries; the 5 that matter most are shown first.

1837
Montgomery County created Montgomery created by the Republic of Texas from Liberty, Washington, and a small part of Austin; Montgomery fully organized.
from Liberty from Washington from Austin
14 December 1837 · Texas Repub. Laws 1837, 2d cong., 1st sess./p. 33
1840
Gained territory Montgomery gained from Harris.
from Harris
25 January 1840 · Texas Repub. Laws 1839, 4th cong./p. 222
1841
Lost territory Montgomery lost to creation of Spring Creek (Judicial County).
to Spring Creek
21 January 1841 · Texas Repub. Laws 1840, 5th cong./p. 49
1842
Lost territory Montgomery lost to creation of Hamilton (Judicial County) and Madison (Judicial County).
to Hamilton to Madison
2 February 1842 · Texas Repub. Laws 1841, 6th cong., 1st sess./pp. 91-93
1845
Became part of Texas Montgomery became a county in the newly-established state of Texas. 29 December 1845 · Texas Repub. Laws 1845, 9th cong., spec. sess./pp. 4-6; U.S. Stat., vol. 9, res. 1 [1845]/p. 108; Van Zandt, 122

Show all 11 changes (6 more, mostly small adjustments)

1837
Montgomery County created Montgomery created by the Republic of Texas from Liberty, Washington, and a small part of Austin; Montgomery fully organized.
from Liberty from Washington from Austin
14 December 1837 · Texas Repub. Laws 1837, 2d cong., 1st sess./p. 33
1838
Boundary clarified Montgomery boundaries defined and clarified (no change).
no change
24 May 1838 · Texas Repub. Laws 1838, 2d cong., 2d sess./p. 45
1840
Gained territory Montgomery gained from Harris.
from Harris
25 January 1840 · Texas Repub. Laws 1839, 4th cong./p. 222
1841
Lost territory Montgomery lost to creation of Spring Creek (Judicial County).
to Spring Creek
21 January 1841 · Texas Repub. Laws 1840, 5th cong./p. 49
1842
Lost territory Montgomery lost to creation of Hamilton (Judicial County) and Madison (Judicial County).
to Hamilton to Madison
2 February 1842 · Texas Repub. Laws 1841, 6th cong., 1st sess./pp. 91-93
c. 1842
Gained territory Montgomery gained from Hamilton (Judicial County), Madison (Judicial County), and Spring Creek (Judicial County) when Republic of Texas Supreme Court ruled judicial counties unconstitutional.
from Hamilton from Madisonfrom Spring Creek
27 June 1842 · "Stockton v. Montgomery" in Dallam, 473-486
1845
Became part of Texas Montgomery became a county in the newly-established state of Texas. 29 December 1845 · Texas Repub. Laws 1845, 9th cong., spec. sess./pp. 4-6; U.S. Stat., vol. 9, res. 1 [1845]/p. 108; Van Zandt, 122
1846
Lost territory Montgomery lost to creation of Grimes and Walker.
to Grimes to Walker
6 April 1846 · Texas Laws 1846, 1st leg./pp. 50-51
1869
Changed Montgomery authorized by Constitutional Convention to lose to creation of San Jacinto (proposed); creation did not take effect.
San Jacinto
5 January 1869 · Gammel, 6: "Ordinances Constitutional Convention 1868," 66
1870
Lost territory Montgomery lost to creation of San Jacinto.
to San Jacinto
13 August 1870 · Texas Laws 1870, 12th leg., called sess., ch. 59/p. 79
1874
Boundary clarified Boundary of San Jacinto with Montgomery and Walker clarified (no change).
with San Jacinto with Walkerno change
8 April 1874 · Texas Laws 1874, 14th leg., reg. sess., ch. 62/p. 71

Land and parcels

What the maps cover in Montgomery

Who publishes each layer, how good it is, and when we last checked.

Parcels Good enough

Lot lines and tax-map numbers for 321,933 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 9 May 2025 · checked 15 October 2026
Address points Official

One point per address, 329,687 in all from Texas Geographic Information Office (TxGIO, formerly TNRIS), a division of the Texas Water Development Board; StratMap program.
checked 14 October 2026
Buildings Reference

Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026

Official: from the office that keeps the record
Good enough: a reliable statewide or national copy
Fallback: a guide only; check the official record
Missing: nothing public found yet

People and land

Montgomery by the Census

Population

620,443 2020 Census count

Housing units

238,489 2020 Census count

Land area

1,042 square miles

Water area

35 square miles

People per sq mi

595 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

Rules and offices

Montgomery County's official site

We have found the county's site but not its offices yet; start there.

County government

County government
The official website of Montgomery County.
mctx.org

See your own lot on these maps

Open Montgomery County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.

Open the free map no sign-in Pro early access

Questions

Common questions about Montgomery County

When was Montgomery County founded?: Montgomery County was founded in 1837, formed from Liberty County, Washington County and Austin County, and named after Montgomery, Texas.
What is the county seat of Montgomery County?: The county seat of Montgomery County is Conroe.
Is there an online parcel map for Montgomery County?: Yes. A public source publishes a parcel map of 321,933 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Montgomery County's boundary or name changed?: Montgomery County was created in 1837 from Liberty County, Washington County and Austin County. Since then the Atlas of Historical County Boundaries records 8 later changes, chiefly involving Hamilton County, Madison County and San Jacinto County.
Is my lot in a flood zone?: We do not have flood maps for Montgomery County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby