Water wells in the upper Trinity (Paluxy and Glen Rose), Mills County, Texas
Only 17 home water wells that draw from the upper Trinity (Paluxy and Glen Rose) in Mills County, Texas have been reported since 2001, so treat this as a rough guide: the middle half are 150 to 210 feet deep (median 174 ft). It is a minor layer here: just 3% of the 178 wells the state's model covers; the main one is the lower Trinity (Twin Mountains and Travis Peak) (88%). They run about 126 feet shallower than the county's median well (300 ft). Estimated cost of a complete well at the median depth: $7,000 to $17,000.
This page is based on fewer than 30 wells, so it is kept out of search engines until more reports come in. Treat every figure as a rough guide.
Updated every day from Texas Water Development Board driller reports. Last update: November 11, 2026, using the state file of November 10, 2026.
Which layer Mills County wells draw from
- Lower Trinity (Twin Mountains and Travis Peak) 88% · 157 wells
- Near or below the base of the Trinity 9% · 16 wells
- Upper Trinity (Paluxy and Glen Rose) 3% · 5 wells
Home wells in Mills County
Each dot is a home well from a state driller report, colored by depth. Tap one for its details and official report. Tap an empty spot to see what is under that point.
Well depth (ft)
- <100
- 100
- 200
- 300
- 400
- 600
- 800+
Dark line: Mills County
Green: aquifer mapped by the state
Key figures
- Typical depth (middle half)
- 150 to 210 feet
- Median depth
- 174 feet
- Deepest 10% are past
- 382 feet
- Water level (median)
- 100 feet
- 15 wells
- Yield (median)
- 8 gpm
- 16 wells, gallons per minute
- Wells used
- 17
- Since 2001
- Share of the county's wells
- 3%
- All years on file
- 17
- median 174 ft, since 2002
- Confidence
- Few wells (10 to 29)
When the wells were finished, the water stood a median 100 feet below the surface (15 wells).
What this layer is
This group is the upper half of the Trinity in North and Central Texas: the Paluxy sand on top and the Glen Rose limestone and marl under it. The state's model draws them as two layers, but our check against the state's own aquifer codes shows the method cannot tell them apart reliably, so this atlas reports them together. North and west of Fort Worth the limestone gives way to sand and both become the upper part of the undivided Antlers Formation.
Depth over time
Too few wells per period in this layer in Mills County to compare depth over time. Since 2002, 17 home wells have been reported, with a median of 174 feet.
| Period | Median depth (ft) | Wells |
|---|---|---|
| 2001–2005 | under 10 wells | 8 |
| 2006–2010 | under 10 wells | 2 |
| 2011–2015 | under 10 wells | 2 |
| 2016–2020 | under 10 wells | 2 |
| 2021–2025 | under 10 wells | 3 |
Common questions
How deep is a well in the upper Trinity (Paluxy and Glen Rose) in Mills County?
Only 17 home water wells that draw from the upper Trinity (Paluxy and Glen Rose) in Mills County, Texas have been reported since 2001, so treat this as a rough guide: the middle half are 150 to 210 feet deep (median 174 ft).
How many Mills County wells draw from this layer?
It is a minor layer here: just 3% of the 178 wells the state's model covers; the main one is the lower Trinity (Twin Mountains and Travis Peak) (88%). Only 29% of these wells have the water-bearing interval on their report (reports before about 2012 rarely do). For the others we use the bottom of the hole, which tends to read one layer deeper than where the water actually comes from.
How deep does the water stand?
When the wells were finished, the water stood a median 100 feet below the surface (15 wells).
What a well costs here
At the median depth for this layer in Mills County (174 feet), a complete home well would cost roughly $7,000 to $17,000: $25 to $60 per foot for drilling, casing and seal, plus $2,500 to $6,500 for the pump, pressure tank, controls and hookup at the well. Across the whole middle half of depths (150 to 210 feet) the range runs from $6,500 to $19,000. This is TerraFunded's estimate from published Texas prices, not a quote, and it leaves out trenching and the line to the house. Get prices from at least two licensed drillers.
How these numbers are made
We count new and replacement domestic (home) wells with a valid depth on their report. We use the last 10 years when there are at least 30 wells; otherwise all since 2001. The median is the middle well and the middle half runs from the 25th to the 75th percentile.
To tell which layer a well draws from, we take the ground elevation at its location, subtract the depth of the interval where water enters (or the bottom of the hole when the report does not give one) and see which layer of the state's model that point falls in.
Only 29% of these wells have the water-bearing interval on their report (reports before about 2012 rarely do). For the others we use the bottom of the hole, which tends to read one layer deeper than where the water actually comes from.
How well it works: In 7,977 wells in the area of the state's Northern Trinity and Woodbine model (North and Central Texas) where the State of Texas recorded the aquifer, our estimate of the formation the well draws from names the same layer of the state's model in about 74% of them, and that layer or the one next to it in at least 95%; among the 3,130 of those wells that the state places in a Trinity layer (Paluxy to Hosston) it is about 56%.
- The layers come from the Texas Water Development Board's Northern Trinity and Woodbine model, with quarter mile cells, summarized here to about 1.3 miles. It is a regional model, not a survey of any lot: between one model point and the next, the real depth of each layer can differ.
- In this model every layer is at least 30 feet thick, even where the real rock is thinner or missing. Thin layers and the edges of the model are approximate.
- Inside the Trinity this atlas does not name single model layers: it groups the Paluxy and Glen Rose (upper Trinity) and groups the Hensell, Pearsall and Hosston (lower Trinity, Twin Mountains and Travis Peak), because the check against the state's codes shows the method cannot separate them reliably.
- "Near or below the base of the Trinity" means the well reaches the bottom of the model or passes it, often by tens of feet. Older rock that the model does not include may lie there.
- We never use the model's water levels. The water level on this page is the one each driller measured when the well was finished.
These are depths of real wells drilled nearby, not a promise about any property. Groundwater can change over short distances and with drought. A licensed water well driller can tell you what to expect on a specific tract.
Read the full methodology · Download the data (CSV, CC BY 4.0)
How to cite
TerraFunded (2026). Texas Well Atlas: Underground. From Texas Water Development Board driller reports and groundwater availability models (data as of November 10, 2026). https://terrafunded.com/wells/mills-county/paluxy-glen-rose. License CC BY 4.0. https://doi.org/10.5281/zenodo.24126380.
Sources
- Submitted Driller's Reports database, Texas Water Development Board (TWDB) (file of November 10, 2026)
- Hydrogeology and Documentation of the Northern Trinity and Woodbine Aquifer System Groundwater Availability Model (NTGAM). Ellis, J., Prieto-Estrada, A., Osborne, A., Deeds, N., White, J., and Keester, M. (INTERA Incorporated), for the North Texas Groundwater Conservation District and Groundwater Management Area 8, 2025, GAM v3.01. TWDB groundwater availability model.
- Ground elevation: Terrain Tiles (Mapzen), Registry of Open Data on AWS
- TWDB well report viewer (each well's official report)
