# Relationship history for MSHA mine 3200780

Current hierarchy: **Ronald H Clark → Clark Gravel & Construction Inc. → Clark Gravel & Construction Inc.**

- 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:** Harvey  Clark → Clark Gravel & Construction Inc.; 1979-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Clark Gravel & Construction Inc. → Clark Gravel & Construction Inc.; 2000-07-01 to 2021-11-25; source msha-controller-operator-history
- **controller_controls_operator:** Harvey  Clark → Clark Gravel & Construction Inc.; 2000-07-01 to 2021-11-25; source msha-controller-operator-history
- **operator_operates_mine:** Clark Gravel & Construction Inc. → Clark Gravel & Construction Inc.; 2021-11-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ronald H  Clark et al → Clark Gravel & Construction Inc.; 2021-11-26 to 2022-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Ronald H  Clark et al → Clark Gravel & Construction Inc.; 2021-11-26 to 2022-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Sherry  Clark et al → Clark Gravel & Construction Inc.; 2021-11-26 to 2022-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Ronald H Clark → Clark Gravel & Construction Inc.; 2023-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ronald H Clark → Clark Gravel & Construction Inc.; 2023-01-01 to current/open; source msha-controller-operator-history