# Relationship history for MSHA mine 4607521

Current hierarchy: **Dennison James G → Last Chance Coal Company Inc → Mine #1**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Last Chance Coal Company Inc → Mine #1; 1988-05-01 to 1988-06-28; source msha-controller-operator-history
- **controller_controls_mine:** Lane Arley → Mine #1; 1988-05-01 to 1988-06-28; source msha-controller-operator-history
- **controller_controls_operator:** Lane Arley → Last Chance Coal Company Inc; 1988-05-01 to 1988-06-28; source msha-controller-operator-history
- **operator_operates_mine:** Last Chance Coal Company Inc → Mine #1; 1988-06-29 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Grimmett Walter R → Mine #1; 1988-06-29 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Grimmett Walter R → Last Chance Coal Company Inc; 1988-06-29 to 1988-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Last Chance Coal Company Inc → Mine #1; 1988-11-14 to 1989-02-07; source msha-controller-operator-history
- **controller_controls_mine:** Harvey Guy D → Mine #1; 1988-11-14 to 1989-02-07; source msha-controller-operator-history
- **controller_controls_operator:** Harvey Guy D → Last Chance Coal Company Inc; 1988-11-14 to 1989-02-07; source msha-controller-operator-history
- **operator_operates_mine:** Last Chance Coal Company Inc → Mine #1; 1989-02-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dennison James G → Mine #1; 1989-02-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennison James G → Last Chance Coal Company Inc; 1989-02-08 to current/open; source msha-controller-operator-history