# Relationship history for MSHA mine 0900157

Current hierarchy: **MFM Delaware → MFM Industries → Waverly Minerals**

- 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:** Waverly Mineral Products Company → Waverly Minerals; 1950-01-01 to 1987-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Johnson-March Corp → Waverly Minerals; 1950-01-01 to 1987-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Johnson-March Corp → Waverly Mineral Products Company; 1950-01-01 to 1987-12-31; source msha-controller-operator-history
- **controller_controls_mine:** MFM Delaware → Waverly Minerals; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Waverly Mineral Products Company → Waverly Minerals; 1988-01-01 to 1996-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Laporte Plc → Waverly Minerals; 1988-01-01 to 1996-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Laporte Plc → Waverly Mineral Products Company; 1988-01-01 to 1996-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Sud-Chemie Adsorbents Inc → Waverly Minerals; 1996-07-01 to 2005-01-30; source msha-controller-operator-history
- **controller_controls_mine:** Sued-Chemie AG → Waverly Minerals; 1996-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sued-Chemie AG → Sud-Chemie Adsorbents Inc; 1996-07-01 to 2005-01-30; source msha-controller-operator-history
- **operator_operates_mine:** MFM Industries → Waverly Minerals; 2005-01-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MFM Delaware → MFM Industries; 2005-01-31 to current/open; source msha-controller-operator-history