# Relationship history for MSHA mine 4606367

Current hierarchy: **Helmick Robert H → Robert H Helmick Inc → No 1 Mabie**

- 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:** Helmick Robert H → No 1 Mabie; 1980-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Associated Land Services → No 1 Mabie; 1981-08-01 to 1982-09-29; source msha-controller-operator-history
- **controller_controls_mine:** Boserman R W → No 1 Mabie; 1981-08-01 to 1982-09-29; source msha-controller-operator-history
- **controller_controls_operator:** Boserman R W → Associated Land Services; 1981-08-01 to 1982-09-29; source msha-controller-operator-history
- **operator_operates_mine:** C W Bentley Inc → No 1 Mabie; 1982-09-30 to 1988-02-16; source msha-controller-operator-history
- **controller_controls_mine:** Chw Industries Inc → No 1 Mabie; 1982-09-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chw Industries Inc → C W Bentley Inc; 1982-09-30 to 1988-02-16; source msha-controller-operator-history
- **operator_operates_mine:** Bentley Coal Company → No 1 Mabie; 1988-02-17 to 1988-05-19; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Amax Minerals Company → No 1 Mabie; 1988-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Amax Minerals Company → Bentley Coal Company; 1988-02-17 to 1988-05-19; source msha-controller-operator-history
- **operator_operates_mine:** Robert H Helmick Inc → No 1 Mabie; 1988-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Helmick Robert H → Robert H Helmick Inc; 1988-05-20 to current/open; source msha-controller-operator-history