# Relationship history for MSHA mine 1502424

Current hierarchy: **Rag Aktiengesellschaft → Standard Sign & Signal Company → May Mine**

- 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

- **controller_controls_mine:** May Victor → May Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hall Coal Company → May Mine; 1950-01-01 to 1973-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Hall Leonard--Gary Thornsberry & George Smith → May Mine; 1950-01-01 to 1976-08-18; source msha-controller-operator-history
- **controller_controls_operator:** Hall Leonard--Gary Thornsberry & George Smith → Hall Coal Company; 1950-01-01 to 1973-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Belcher Jack R & Bobby Merrett → May Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Black Nuggett Coal Company → May Mine; 1973-05-01 to 1974-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Belcher Jack R & Bobby Merrett → Black Nuggett Coal Company; 1973-05-01 to 1974-06-30; source msha-controller-operator-history
- **operator_operates_mine:** May Coal Company → May Mine; 1974-07-01 to 1975-02-23; source msha-controller-operator-history
- **controller_controls_operator:** May Victor → May Coal Company; 1974-07-01 to 1975-02-23; source msha-controller-operator-history
- **controller_controls_mine:** Rag Aktiengesellschaft → May Mine; 1974-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Standard Sign & Signal Company → May Mine; 1975-02-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rag Aktiengesellschaft → Standard Sign & Signal Company; 1975-02-24 to current/open; source msha-controller-operator-history