# Relationship history for MSHA mine 1200634

Current hierarchy: **Waste Management Inc → CGS Services Inc → Caldwell PT & ML**

- 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:** Caldwell Gravel Sales Inc → Caldwell PT & ML; 1950-01-01 to 2002-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Dana I  Caldwell → Caldwell PT & ML; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dana I  Caldwell → Caldwell Gravel Sales Inc; 1950-01-01 to 2002-12-31; source msha-controller-operator-history
- **operator_operates_mine:** CGS Services Inc → Caldwell PT & ML; 2003-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dana I  Caldwell → Caldwell PT & ML; 2003-01-01 to 2017-02-02; source msha-controller-operator-history
- **controller_controls_operator:** Dana I  Caldwell → CGS Services Inc; 2003-01-01 to 2017-02-02; source msha-controller-operator-history
- **controller_controls_mine:** Advanced Disposal Services → Caldwell PT & ML; 2017-02-03 to 2021-06-29; source msha-controller-operator-history
- **controller_controls_operator:** Advanced Disposal Services → CGS Services Inc; 2017-02-03 to 2021-06-29; source msha-controller-operator-history
- **controller_controls_mine:** Waste Management Inc → Caldwell PT & ML; 2021-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Waste Management Inc → CGS Services Inc; 2021-06-30 to current/open; source msha-controller-operator-history