# Relationship history for MSHA mine 1519843

Current hierarchy: **Bridgett  Howard → K Tech Enterprises Inc → K Tech Enterprise**

- 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:** K Tech Enterprises Inc → K Tech Enterprise; 2018-10-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bridgett  Howard → K Tech Enterprise; 2018-10-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bridgett  Howard → K Tech Enterprises Inc; 2018-10-04 to current/open; source msha-controller-operator-history