# Relationship history for MSHA mine 4202494

Current hierarchy: **Chris A  Boyer → FRP Services, Inc. → Portable #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:** Chris A  Boyer → Portable #1; 2004-04-05 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Flare Construction Inc → Portable #1; 2008-03-03 to 2016-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Chris A  Boyer → Flare Construction Inc; 2008-03-03 to 2016-07-31; source msha-controller-operator-history
- **operator_operates_mine:** FRP Services, Inc. → Portable #1; 2016-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Chris A  Boyer → Portable #1; 2016-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chris A  Boyer → FRP Services, Inc.; 2016-08-01 to current/open; source msha-controller-operator-history