# Relationship history for MSHA mine 4503333

Current hierarchy: **John  Quigg; Neil  Quigg → Quigg Brothers-Schermer Inc → CRUSHER PLANT #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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Schermer Construction Inc → CRUSHER PLANT #1; 1994-11-01 to 1996-07-21; source msha-controller-operator-history
- **controller_controls_mine:** Douglas  Schermer → CRUSHER PLANT #1; 1994-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Douglas  Schermer → Schermer Construction Inc; 1994-11-01 to 1996-07-21; source msha-controller-operator-history
- **operator_operates_mine:** Quigg Brothers-Schermer Inc → CRUSHER PLANT #1; 1996-07-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Neil  Quigg et al → CRUSHER PLANT #1; 1996-07-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Neil  Quigg et al → Quigg Brothers-Schermer Inc; 1996-07-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John  Quigg et al → Quigg Brothers-Schermer Inc; 1996-07-22 to current/open; source msha-controller-operator-history