# Relationship history for MSHA mine 0501887

Current hierarchy: **Exxon Corp → Exxon Mobil Corporation → Colony Oil Shale Project**

- 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

- **controller_controls_mine:** Exxon Corp → Colony Oil Shale Project; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Colony Development Operation → Colony Oil Shale Project; 1950-01-01 to 1980-12-09; source msha-controller-operator-history
- **controller_controls_mine:** Atlantic Richfield Company & Tosco Corp → Colony Oil Shale Project; 1950-01-01 to 1980-12-09; source msha-controller-operator-history
- **controller_controls_operator:** Atlantic Richfield Company & Tosco Corp → Colony Development Operation; 1950-01-01 to 1980-12-09; source msha-controller-operator-history
- **operator_operates_mine:** Exxon Mobil Corporation → Colony Oil Shale Project; 1980-12-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Exxon Corp → Exxon Mobil Corporation; 1980-12-10 to current/open; source msha-controller-operator-history