When was Castro County founded?

Castro County was founded in 1876, formed from Jack County, and named after Henri Castro.

What is the county seat of Castro County?

The county seat of Castro County is Dimmitt.

Is there an online parcel map for Castro County?

Yes. Castro County publishes a parcel map of 6,461 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Castro County's boundary or name changed?

Castro County was created in 1876 from Jack County. Since then the Atlas of Historical County Boundaries records 6 later changes, chiefly involving Bailey County, Lamb County and Oldham County.

Is my lot in a flood zone?

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

County · code 48069

Castro CountyTexas

Castro County is a county in Texas with its seat in Dimmitt. It was created on November 19, 1876, from Jack Territory and named after Henri Castro.

Founded1876
County seatDimmitt
Named forHenri Castro
Land area894 sq mi + 4.9 sq mi water
Population7,371 2020 Census
Parcels mapped6,461 checked 14 October 2026

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

Updated 19 October 2026

Census outline · seat marked

History

Formed in 1876 from Jack County

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

Castro County was created from Jack Territory on November 19, 1876, but was not fully organized at that time and was attached to Jack County for judicial and other purposes. Over the following decades, Castro was attached to Wheeler County in 1879, then to Oldham County in 1881, before becoming fully organized and independent on December 21, 1891. In 1892, Bailey and Lamb counties were attached to Castro for judicial purposes, though Lamb County was fully organized and detached in 1908, followed by Bailey County by 1919.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries.

1876
Castro County created Castro created from Young Territory; Castro not fully organized, attached to Jack "for judicial, surveying and all other purposes." Act passed 21 August 1876; took effect 19 November 1876.
from Jack
19 November 1876 · Texas Laws 1876, 15th leg., ch. 144/pp. 237, 242
1879
Changed Castro detached from Jack, attached to Wheeler "for judicial purposes."
Jack Wheeler
7 October 1879 · Texas Laws 1879, 16th leg., spec. sess., ch. 30, sec. 3/p. 29
1881
Changed Castro detached from Wheeler, attached to Oldham "for judicial purposes."
Wheeler Oldham
15 February 1881 · Texas Laws 1881, 17th leg., reg. sess., ch. 13, sec. 5/p. 8
1891
Changed Castro fully organized, detached from Oldham.
Oldham
21 December 1891 · "Castro County," New Handbook of Texas, 1:1022
1892
Changed Bailey and Lamb detached from Hale, both attached to Castro "for judicial purposes."
Bailey Lamb Hale
1 September 1892 · Texas Laws 1892, 22d leg., called sess., ch. 24, sec. 2/p. 59
1908
Changed Lamb fully organized, detached from Castro.
Lamb
20 June 1908 · "Lamb County," New Handbook of Texas, 4:44
c. 1919
Changed Bailey fully organized, detached from Castro.
Bailey
17 March 1919 · Kennedy, 61; Texas Laws 1919, 36th leg., reg. sess., ch. 82, sec. 2/p. 132

Land and parcels

What the maps cover in Castro

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

Parcels Good enough

Lot lines and tax-map numbers for 6,461 parcels from Castro County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
checked 14 October 2026
Address points Official

One point per address, 3,893 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

Castro by the Census

Population

7,371 2020 Census count

Housing units

3,016 2020 Census count

Land area

894 square miles

Water area

4.9 square miles

People per sq mi

8 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

Castro 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 Castro County.
co.castro.tx.us

See your own lot on these maps

Open Castro 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 Castro County

When was Castro County founded?: Castro County was founded in 1876, formed from Jack County, and named after Henri Castro.
What is the county seat of Castro County?: The county seat of Castro County is Dimmitt.
Is there an online parcel map for Castro County?: Yes. Castro County publishes a parcel map of 6,461 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Castro County's boundary or name changed?: Castro County was created in 1876 from Jack County. Since then the Atlas of Historical County Boundaries records 6 later changes, chiefly involving Bailey County, Lamb County and Oldham County.
Is my lot in a flood zone?: We do not have flood maps for Castro County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby