# Relationship history for MSHA mine 3600155

Current hierarchy: **Shelly  Snoddy → Coolspring Stone Supply Inc → COOLSPRING MINING 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

- **operator_operates_mine:** Martin Marietta Aggregates → COOLSPRING MINING INC; 1950-01-01 to 1981-06-28; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → COOLSPRING MINING INC; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1950-01-01 to 1981-06-28; source msha-controller-operator-history
- **operator_operates_mine:** Coolspring Stone Supply Inc → COOLSPRING MINING INC; 1981-06-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** William R  Snoddy  et al → COOLSPRING MINING INC; 1981-06-29 to 2015-04-20; source msha-controller-operator-history
- **controller_controls_operator:** William R  Snoddy  et al → Coolspring Stone Supply Inc; 1981-06-29 to 2015-04-20; source msha-controller-operator-history
- **controller_controls_mine:** Patricia  Snoddy → COOLSPRING MINING INC; 2015-04-21 to 2024-02-19; source msha-controller-operator-history
- **controller_controls_operator:** Patricia  Snoddy → Coolspring Stone Supply Inc; 2015-04-21 to 2024-02-19; source msha-controller-operator-history
- **controller_controls_mine:** Shelly  Snoddy → COOLSPRING MINING INC; 2024-02-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shelly  Snoddy → Coolspring Stone Supply Inc; 2024-02-20 to current/open; source msha-controller-operator-history