# Relationship history for MSHA mine 1601553

Current hierarchy: **Dunn Investment Company → Hard Rock Sand and Gravel → Hard Rock Sand and Gravel**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** James J  Denman → Hard Rock Sand and Gravel; 2002-06-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hard Rock Sand & Gravel LLC → Hard Rock Sand and Gravel; 2015-09-02 to 2021-01-03; source msha-controller-operator-history
- **controller_controls_operator:** James J  Denman → Hard Rock Sand & Gravel LLC; 2015-09-02 to 2021-01-03; source msha-controller-operator-history
- **operator_operates_mine:** Hard Rock Sand and Gravel → Hard Rock Sand and Gravel; 2021-01-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rodney  Grogan et al → Hard Rock Sand and Gravel; 2021-01-04 to 2022-05-16; source msha-controller-operator-history
- **controller_controls_operator:** Rodney  Grogan et al → Hard Rock Sand and Gravel; 2021-01-04 to 2022-05-16; source msha-controller-operator-history
- **controller_controls_operator:** Eddie  Middleton et al → Hard Rock Sand and Gravel; 2021-01-04 to 2022-05-16; source msha-controller-operator-history
- **controller_controls_mine:** Dunn Investment Company → Hard Rock Sand and Gravel; 2022-05-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dunn Investment Company → Hard Rock Sand and Gravel; 2022-05-17 to current/open; source msha-controller-operator-history