# Relationship history for MSHA mine 1516478

Current hierarchy: **Harold K  Simpson → Simpson Mining Co., Inc. → Delphia 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:** Blue Diamond Coal Company → Delphia Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Harold K  Simpson → Delphia Mine; 1986-09-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Blue Diamond Coal Company → Delphia Mine; 1988-09-01 to 1991-08-18; source msha-controller-operator-history
- **controller_controls_operator:** Blue Diamond Coal Company → Blue Diamond Coal Company; 1988-09-01 to 1991-08-18; source msha-controller-operator-history
- **controller_controls_mine:** James A  Hubbard → Delphia Mine; 1991-08-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Leatherwood Energy Corp Inc → Delphia Mine; 1991-08-19 to 1995-04-03; source msha-controller-operator-history
- **controller_controls_mine:** Richard B  Combs et al → Delphia Mine; 1991-08-19 to 1995-04-03; source msha-controller-operator-history
- **controller_controls_operator:** Richard B  Combs et al → Leatherwood Energy Corp Inc; 1991-08-19 to 1995-04-03; source msha-controller-operator-history
- **operator_operates_mine:** Hubb Corp → Delphia Mine; 1995-04-04 to 2001-08-10; source msha-controller-operator-history
- **controller_controls_operator:** James A  Hubbard → Hubb Corp; 1995-04-04 to 2001-08-10; source msha-controller-operator-history
- **operator_operates_mine:** Simpson Mining Co., Inc. → Delphia Mine; 2001-08-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harold K  Simpson → Simpson Mining Co., Inc.; 2001-08-11 to current/open; source msha-controller-operator-history