# Relationship history for MSHA mine 4502282

Current hierarchy: **Walt  Miles → Miles Sand & Gravel Company → Shelton 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Walt  Miles et al → Shelton Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Graystone Inc → Shelton Pit; 1950-01-01 to 1985-05-15; source msha-controller-operator-history
- **controller_controls_mine:** Graystone Corp → Shelton Pit; 1950-01-01 to 1985-05-15; source msha-controller-operator-history
- **controller_controls_operator:** Graystone Corp → Graystone Inc; 1950-01-01 to 1985-05-15; source msha-controller-operator-history
- **controller_controls_mine:** Harbor Resources → Shelton Pit; 1985-05-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cascade Pumice Inc → Shelton Pit; 1985-05-16 to 1989-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Harbor Resources → Cascade Pumice Inc; 1985-05-16 to 1989-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Miles Sand & Gravel Company → Shelton Pit; 1989-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walt  Miles et al → Miles Sand & Gravel Company; 1989-05-01 to current/open; source msha-controller-operator-history