# Relationship history for MSHA mine 3609641

Current hierarchy: **Robert E  Yarger → K A M C → Kovatch 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

- **controller_controls_mine:** Alvin J  Roman → Kovatch 1; 1996-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert E  Yarger → Kovatch 1; 2003-01-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert E  Yarger → Kovatch 1; 2005-12-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** No 1 Contracting Corporation → Kovatch 1; 2008-07-01 to 2009-08-13; source msha-controller-operator-history
- **controller_controls_operator:** Alvin J  Roman → No 1 Contracting Corporation; 2008-07-01 to 2009-08-13; source msha-controller-operator-history
- **operator_operates_mine:** K A Ash LTD → Kovatch 1; 2009-08-14 to 2009-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Robert E  Yarger → K A Ash LTD; 2009-08-14 to 2009-09-14; source msha-controller-operator-history
- **operator_operates_mine:** K A M C → Kovatch 1; 2009-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert E  Yarger → K A M C; 2009-09-15 to current/open; source msha-controller-operator-history