# Relationship history for MSHA mine 1505418

Current hierarchy: **Bowling Charles D → Crystal Coal Company → No 2 (D)**

- 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

- **operator_operates_mine:** Kojax Mining Company → No 2 (D); 1950-01-01 to 1976-02-26; source msha-controller-operator-history
- **controller_controls_mine:** Davis Gene → No 2 (D); 1950-01-01 to 1976-02-26; source msha-controller-operator-history
- **controller_controls_operator:** Davis Gene → Kojax Mining Company; 1950-01-01 to 1976-02-26; source msha-controller-operator-history
- **controller_controls_mine:** Michael  Derry et al → No 2 (D); 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bowling Charles D Et Al → No 2 (D); 1973-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bentley & Derry Coal Company Inc → No 2 (D); 1976-02-27 to 1977-04-19; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Derry et al → Bentley & Derry Coal Company Inc; 1976-02-27 to 1977-04-19; source msha-controller-operator-history
- **controller_controls_operator:** James E Derry et al → Bentley & Derry Coal Company Inc; 1976-02-27 to 1977-04-19; source msha-controller-operator-history
- **operator_operates_mine:** Huffman & Hall Coal Company Inc → No 2 (D); 1977-04-20 to 1978-04-05; source msha-controller-operator-history
- **controller_controls_mine:** Huffman Denesel & Woody Hall → No 2 (D); 1977-04-20 to 1978-04-05; source msha-controller-operator-history
- **controller_controls_operator:** Huffman Denesel & Woody Hall → Huffman & Hall Coal Company Inc; 1977-04-20 to 1978-04-05; source msha-controller-operator-history
- **controller_controls_mine:** Smallwood Lenard → No 2 (D); 1978-02-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cobra Mining Company Inc → No 2 (D); 1978-04-06 to 1978-09-12; source msha-controller-operator-history
- **controller_controls_mine:** Epling Thomas E → No 2 (D); 1978-04-06 to 1978-09-12; source msha-controller-operator-history
- **controller_controls_operator:** Epling Thomas E → Cobra Mining Company Inc; 1978-04-06 to 1978-09-12; source msha-controller-operator-history
- **operator_operates_mine:** Derry Mining Company Inc → No 2 (D); 1978-09-13 to 1979-06-18; source msha-controller-operator-history
- **controller_controls_mine:** James E Derry et al → No 2 (D); 1978-09-13 to 1979-06-18; source msha-controller-operator-history
- **controller_controls_operator:** James E Derry et al → Derry Mining Company Inc; 1978-09-13 to 1979-06-18; source msha-controller-operator-history
- **operator_operates_mine:** Lenard Mining Company → No 2 (D); 1979-06-19 to 1980-05-29; source msha-controller-operator-history
- **controller_controls_operator:** Smallwood Lenard → Lenard Mining Company; 1979-06-19 to 1980-05-29; source msha-controller-operator-history
- **operator_operates_mine:** Crystal Coal Company → No 2 (D); 1980-05-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bowling Charles D Et Al → Crystal Coal Company; 1980-05-30 to current/open; source msha-controller-operator-history