Key Takeaway

Rio Medina is a active surface mine producing Stone, located in San Antonio, Medina County, TX. It has 158 violations on record (38 S&S) and $51K in proposed penalties. Operated by Martin Marietta Materials Southwest LLC.

Rio Medina

Active Surface Stone

Operator: Martin Marietta Materials Southwest LLC

Controller: Martin Marietta Materials Inc

Location: San Antonio, Medina County, TX

Employees: 16

158
Violations
38
S&S Violations
6
Accidents
$51K
Penalties

Recent Violations

View all 158 →
Date Section S&S Negligence Penalty
10/30/2025 56.14207 Non-S&S LowNegligence $151
10/30/2025 56.18002(b) Non-S&S ModNegligence $151
10/30/2025 56.18002(c) Non-S&S ModNegligence $151
10/29/2025 56.12032 Non-S&S LowNegligence $151
10/29/2025 56.12018 Non-S&S LowNegligence $151
10/07/2024 56.18010 Non-S&S ModNegligence $147
10/02/2024 56.14107(a) Non-S&S LowNegligence $147
10/02/2024 48.29(a) Non-S&S ModNegligence $147
07/24/2024 56.12008 Non-S&S ModNegligence $239
07/05/2023 56.20003(a) Non-S&S ModNegligence $143
07/05/2023 56.11012 S&S ModNegligence $346
07/05/2023 56.11002 S&S ModNegligence $346
07/05/2023 56.12004 Non-S&S ModNegligence $232
07/05/2023 56.12004 Non-S&S ModNegligence $232
09/13/2022 56.4201(a)(1) Non-S&S ModNegligence $133
09/13/2022 56.14107(a) S&S ModNegligence $183
09/13/2022 56.14207 Non-S&S ModNegligence $133
09/13/2022 56.12030 Non-S&S ModNegligence $442
09/13/2022 56.14101(a)(2) Non-S&S ModNegligence $133
09/12/2022 56.20003(a) Non-S&S ModNegligence $133

Accidents & Injuries

View all 6 →
Date Classification Injury Days Lost
04/12/2024 HANDLING OF MATERIALS NO DYS AWY FRM WRK,NO RSTR ACT None
07/10/2023 HANDLING OF MATERIALS DAYS RESTRICTED ACTIVITY ONLY 17d restricted
02/09/2023 MACHINERY DAYS RESTRICTED ACTIVITY ONLY 1d restricted
10/26/2022 HANDLING OF MATERIALS DAYS RESTRICTED ACTIVITY ONLY 100d restricted
10/11/2019 HANDLING OF MATERIALS DAYS RESTRICTED ACTIVITY ONLY 35d restricted
11/10/2005 HANDTOOLS (NONPOWERED) NO DYS AWY FRM WRK,NO RSTR ACT None

Inspections

View all 66 →
Begin End Hours Inspectors
10/29/2025 10/30/2025 18.75 1
08/12/2025 08/12/2025 10.00 1
10/01/2024 10/17/2024 26.00 1
07/24/2024 07/24/2024 0.00 0
03/13/2024 03/13/2024 6.50 1
07/05/2023 07/10/2023 23.00 1
03/13/2023 03/20/2023 20.00 1
09/14/2022 09/14/2022 2.00 1
09/12/2022 09/13/2022 20.00 1
11/08/2021 11/09/2021 15.75 1

Mine Details

MSHA Mine ID4103594
Mine TypeSurface
StatusActive
CommodityStone
SIC DescriptionCrushed, Broken Limestone NEC
Employees16
Days/Week5.0
Hours/Shift8.0
Coordinates29.5375000, -98.8719440
Nearest TownSan Antonio

Related Mines

Bridgeport Stone Plant
Bridgeport, Wise County, TX
320 violations Active
Beckmann Quarry
San Antonio, Bexar County, TX
252 violations Active
North Austin Quarry
Georgetown, Williamson County, TX
204 violations Active
Mill Creek Limestone Quarry
Mill Creek, Johnston County, OK
171 violations Active
FM 1283
Helotes, Medina County, TX
169 violations Active
Webberville S&G
Manor, Travis County, TX
153 violations Active
Black Spur Quarry
Uvalde, Uvalde County, TX
150 violations Active
Garfield Sand & Gravel
Austin, Travis County, TX
144 violations Active

Frequently Asked Questions

How many MSHA violations does Rio Medina have?

Rio Medina has 158 MSHA violations on record, of which 38 are classified as Significant & Substantial (S&S). Total proposed penalties amount to $51K.

What type of mine is Rio Medina?

Rio Medina is a Surface mine producing Stone, located in San Antonio, Medina County, TX. It currently has 16 employees.

Has anyone been injured or killed at Rio Medina?

According to MSHA records, Rio Medina has 6 reported accident/injury records and 0 fatalities on file.

Who operates Rio Medina?

Rio Medina is operated by Martin Marietta Materials Southwest LLC and controlled by Martin Marietta Materials Inc. MSHA Mine ID: 4103594.