# Relationship history for MSHA mine 1202128

Current hierarchy: **Graber Jesse Jr → Frontier Coal Company Inc → Frontier #3**

- 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:** Francis William → Frontier #3; 1992-07-01 to 1993-03-17; source msha-controller-operator-history
- **operator_operates_mine:** Northern Coal Company Inc → Frontier #3; 1992-12-01 to 1993-03-17; source msha-controller-operator-history
- **controller_controls_operator:** Francis William → Northern Coal Company Inc; 1992-12-01 to 1993-03-17; source msha-controller-operator-history
- **controller_controls_mine:** Romero Richard → Frontier #3; 1993-02-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Excel Resources Inc → Frontier #3; 1993-03-18 to 1993-05-04; source msha-controller-operator-history
- **controller_controls_mine:** Fuller Larry → Frontier #3; 1993-03-18 to 1993-05-04; source msha-controller-operator-history
- **controller_controls_operator:** Fuller Larry → Excel Resources Inc; 1993-03-18 to 1993-05-04; source msha-controller-operator-history
- **controller_controls_mine:** Graber Jesse Jr Et Al → Frontier #3; 1993-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Northern Coal Company Inc → Frontier #3; 1993-05-05 to 1994-03-22; source msha-controller-operator-history
- **controller_controls_operator:** Romero Richard → Northern Coal Company Inc; 1993-05-05 to 1994-03-22; source msha-controller-operator-history
- **operator_operates_mine:** Frontier Coal Company Inc → Frontier #3; 1994-03-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Graber Jesse Jr Et Al → Frontier Coal Company Inc; 1994-03-23 to current/open; source msha-controller-operator-history