# Relationship history for MSHA mine 0201221

Current hierarchy: **CCI  (Clyde Companies Inc) → W W Clyde & Co. → Airport 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:** CKC Materials Division → Airport Pit; 1950-01-01 to 2017-05-31; source msha-controller-operator-history
- **controller_controls_mine:** David D  Cluff  et al → Airport Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David D  Cluff  et al → CKC Materials Division; 1950-01-01 to 2017-05-31; source msha-controller-operator-history
- **controller_controls_mine:** CCI  (Clyde Companies Inc) → Airport Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** CKC CONSTRUCTION → Airport Pit; 2017-06-01 to 2026-05-31; source msha-controller-operator-history
- **controller_controls_mine:** David  Cluff et al → Airport Pit; 2017-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Cluff et al → CKC CONSTRUCTION; 2017-06-01 to 2026-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Justin  Cluff et al → CKC CONSTRUCTION; 2017-06-01 to 2026-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Brian  Cluff et al → CKC CONSTRUCTION; 2017-06-01 to 2026-05-31; source msha-controller-operator-history
- **operator_operates_mine:** W W Clyde & Co. → Airport Pit; 2026-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CCI  (Clyde Companies Inc) → W W Clyde & Co.; 2026-06-01 to current/open; source msha-controller-operator-history