# Relationship history for MSHA mine 3607446

Current hierarchy: **David C  Klementik → Quemahoning Collieries 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Quemahoning Collieries → Mine #1; 1983-03-01 to 1993-01-28; source msha-controller-operator-history
- **controller_controls_mine:** John  Toth et al → Mine #1; 1983-03-01 to 1993-01-28; source msha-controller-operator-history
- **controller_controls_operator:** John  Toth et al → Quemahoning Collieries; 1983-03-01 to 1993-01-28; source msha-controller-operator-history
- **operator_operates_mine:** Quemahoning Collieries Inc → Mine #1; 1993-01-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David C  Klementik  et al → Mine #1; 1993-01-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David C  Klementik  et al → Quemahoning Collieries Inc; 1993-01-29 to current/open; source msha-controller-operator-history