# Relationship history for MSHA mine 1511508

Current hierarchy: **Johnson Ersel → Sher-Mel Coal Company Inc → No 2a 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:** Collins Lonnie R → No 2a Mine; 1976-02-06 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bent Mountain Coal Company Inc → No 2a Mine; 1978-08-01 to 1979-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Collins Lonnie R → Bent Mountain Coal Company Inc; 1978-08-01 to 1979-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Diamond Energy Inc → No 2a Mine; 1979-08-01 to 1980-02-25; source msha-controller-operator-history
- **controller_controls_mine:** Stacy W S → No 2a Mine; 1979-08-01 to 1980-02-25; source msha-controller-operator-history
- **controller_controls_operator:** Stacy W S → Diamond Energy Inc; 1979-08-01 to 1980-02-25; source msha-controller-operator-history
- **operator_operates_mine:** C & R Coal Company → No 2a Mine; 1980-02-26 to 1988-02-17; source msha-controller-operator-history
- **controller_controls_mine:** Salmons Carlos → No 2a Mine; 1980-02-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Salmons Carlos → C & R Coal Company; 1980-02-26 to 1988-02-17; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Ersel → No 2a Mine; 1982-04-06 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sher-Mel Coal Company Inc → No 2a Mine; 1988-02-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Ersel → Sher-Mel Coal Company Inc; 1988-02-18 to current/open; source msha-controller-operator-history