# Relationship history for MSHA mine 4103140

Current hierarchy: **EF Sand and Gravel LLC → South Texas Sand & Gravel LLC → ALTO BONITO GRAVEL PIT**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Alto Bonito Gravel Plant → ALTO BONITO GRAVEL PIT; 1982-10-01 to 1999-12-14; source msha-controller-operator-history
- **controller_controls_mine:** Conrado  Guerra → ALTO BONITO GRAVEL PIT; 1982-10-01 to 1999-12-14; source msha-controller-operator-history
- **controller_controls_operator:** Conrado  Guerra → Alto Bonito Gravel Plant; 1982-10-01 to 1999-12-14; source msha-controller-operator-history
- **operator_operates_mine:** Starr Aggregates Llc → ALTO BONITO GRAVEL PIT; 1999-12-15 to 2019-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Noe  Paredes-Salazar et al → ALTO BONITO GRAVEL PIT; 1999-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Noe  Paredes-Salazar et al → Starr Aggregates Llc; 1999-12-15 to 2019-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Melba  Reynolds et al → Starr Aggregates Llc; 1999-12-15 to 2019-11-30; source msha-controller-operator-history
- **operator_operates_mine:** South Texas Sand & Gravel LLC → ALTO BONITO GRAVEL PIT; 2019-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Epigmenio  Falcon et al → ALTO BONITO GRAVEL PIT; 2019-12-01 to 2022-05-11; source msha-controller-operator-history
- **controller_controls_operator:** Epigmenio  Falcon et al → South Texas Sand & Gravel LLC; 2019-12-01 to 2022-05-11; source msha-controller-operator-history
- **controller_controls_operator:** Melba  Reynolds et al → South Texas Sand & Gravel LLC; 2019-12-01 to 2022-05-11; source msha-controller-operator-history
- **controller_controls_mine:** EF Sand and Gravel LLC → ALTO BONITO GRAVEL PIT; 2022-05-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** EF Sand and Gravel LLC → South Texas Sand & Gravel LLC; 2022-05-12 to current/open; source msha-controller-operator-history