# Relationship history for MSHA mine 1800686

Current hierarchy: **Driggs John → Southern Maryland Sand & Gravel Corp → Piney Church Road Pit**

- 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:** Somar Paving Corp → Piney Church Road Pit; 1981-06-01 to 1986-07-22; source msha-controller-operator-history
- **controller_controls_mine:** Malloy J Kevin → Piney Church Road Pit; 1981-06-01 to 1986-07-22; source msha-controller-operator-history
- **controller_controls_operator:** Malloy J Kevin → Somar Paving Corp; 1981-06-01 to 1986-07-22; source msha-controller-operator-history
- **operator_operates_mine:** Southern Maryland Sand & Gravel Corp → Piney Church Road Pit; 1986-07-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Driggs John → Piney Church Road Pit; 1986-07-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Driggs John → Southern Maryland Sand & Gravel Corp; 1986-07-23 to current/open; source msha-controller-operator-history