# Relationship history for MSHA mine 4700755

Current hierarchy: **Martin Marietta Materials Inc → Barton Sand & Gravel → CEMSTONE 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Casey Gravel Works → CEMSTONE PIT; 1950-01-01 to 1979-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Frank P  Casey → CEMSTONE PIT; 1950-01-01 to 1979-07-09; source msha-controller-operator-history
- **controller_controls_operator:** Frank P  Casey → Casey Gravel Works; 1950-01-01 to 1979-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Eugene  Barton → CEMSTONE PIT; 1950-01-01 to 1983-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Cemstone Ready Mix Inc → CEMSTONE PIT; 1979-07-10 to 1981-07-07; source msha-controller-operator-history
- **controller_controls_mine:** Hammond T Becken et al → CEMSTONE PIT; 1979-07-10 to 2024-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Hammond T Becken et al → Cemstone Ready Mix Inc; 1979-07-10 to 1981-07-07; source msha-controller-operator-history
- **controller_controls_operator:** Tim L Becken et al → Cemstone Ready Mix Inc; 1979-07-10 to 1981-07-07; source msha-controller-operator-history
- **operator_operates_mine:** Barton Contracting Company → CEMSTONE PIT; 1981-07-08 to 1983-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Eugene  Barton → Barton Contracting Company; 1981-07-08 to 1983-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Barton Sand & Gravel → CEMSTONE PIT; 1983-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tiller Corp → CEMSTONE PIT; 1983-03-01 to 2021-05-03; source msha-controller-operator-history
- **controller_controls_operator:** Tiller Corp → Barton Sand & Gravel; 1983-03-01 to 2021-05-03; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → CEMSTONE PIT; 2021-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Barton Sand & Gravel; 2021-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thorwald L  Becken et al → CEMSTONE PIT; 2024-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thorwald L  Becken et al → Cemstone Ready Mix Inc; 2024-10-01 to 1981-07-07; source msha-controller-operator-history
- **controller_controls_operator:** Tim L  Becken et al → Cemstone Ready Mix Inc; 2024-10-01 to 1981-07-07; source msha-controller-operator-history