# Relationship history for MSHA mine 3608405

Current hierarchy: **Kroh Richard Sr-Robert Donton → Sky High Coal Company → Lv #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

- **operator_operates_mine:** Sky High Coal Company → Lv #3; 1993-04-01 to 1993-11-23; source msha-controller-operator-history
- **controller_controls_mine:** Larry  Madenford et al → Lv #3; 1993-04-01 to 1993-11-23; source msha-controller-operator-history
- **controller_controls_operator:** Larry  Madenford et al → Sky High Coal Company; 1993-04-01 to 1993-11-23; source msha-controller-operator-history
- **operator_operates_mine:** Sky High Coal Company → Lv #3; 1993-11-24 to 1995-02-23; source msha-controller-operator-history
- **controller_controls_mine:** Kocher Richard D Et Al → Lv #3; 1993-11-24 to 1995-02-23; source msha-controller-operator-history
- **controller_controls_operator:** Kocher Richard D Et Al → Sky High Coal Company; 1993-11-24 to 1995-02-23; source msha-controller-operator-history
- **operator_operates_mine:** Sky High Coal Company → Lv #3; 1995-02-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kroh Richard Sr-Robert Donton Et Al → Lv #3; 1995-02-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kroh Richard Sr-Robert Donton Et Al → Sky High Coal Company; 1995-02-24 to current/open; source msha-controller-operator-history