# Relationship history for MSHA mine 1002342

Current hierarchy: **Terry  Frost; Guy  Smith; Marilyn  Frost → Rock Placing Co. → Rock Placing Co.**

- 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:** Rock Placing Co. → Rock Placing Co.; 2022-07-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Terry  Frost et al → Rock Placing Co.; 2022-07-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Terry  Frost et al → Rock Placing Co.; 2022-07-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Marilyn  Frost et al → Rock Placing Co.; 2022-07-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Guy  Smith et al → Rock Placing Co.; 2022-07-28 to current/open; source msha-controller-operator-history