# Relationship history for MSHA mine 0402841

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Northern California Aggregates,LLC → Merced Aggregates**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Flintkote Cement Company → Merced Aggregates; 1950-01-01 to 1980-04-06; source msha-controller-operator-history
- **controller_controls_mine:** Flintkote Company → Merced Aggregates; 1950-01-01 to 1980-04-06; source msha-controller-operator-history
- **controller_controls_operator:** Flintkote Company → Flintkote Cement Company; 1950-01-01 to 1980-04-06; source msha-controller-operator-history
- **operator_operates_mine:** Calaveras Materials Inc → Merced Aggregates; 1980-04-07 to 1999-05-11; source msha-controller-operator-history
- **controller_controls_mine:** Cimenteries Cbr Cementbedrijven → Merced Aggregates; 1980-04-07 to 1999-05-26; source msha-controller-operator-history
- **controller_controls_operator:** Cimenteries Cbr Cementbedrijven → Calaveras Materials Inc; 1980-04-07 to 1999-05-11; source msha-controller-operator-history
- **operator_operates_mine:** Calaveras Materials LLC → Merced Aggregates; 1999-05-12 to 2023-01-19; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Merced Aggregates; 1999-05-12 to 2021-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Calaveras Materials LLC; 1999-05-12 to 2021-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Merced Aggregates; 2005-09-15 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Merced Aggregates; 2007-08-23 to 2021-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Merced Aggregates; 2021-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Calaveras Materials LLC; 2021-10-01 to 2023-01-19; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Northern California Aggregates,LLC → Merced Aggregates; 2023-01-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Martin Marietta Northern California Aggregates,LLC; 2023-01-20 to 2021-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Northern California Aggregates,LLC; 2023-01-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Martin Marietta Northern California Aggregates,LLC; 2023-01-20 to 2007-08-22; source msha-controller-operator-history