# Relationship history for MSHA mine 3300170

Current hierarchy: **Graymont Ltd → Graymont Dolime (Oh) Inc → Graymont Dolime (OH) Inc.**

- 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:** United States Gypsum Company → Graymont Dolime (OH) Inc.; 1950-01-01 to 1989-11-07; source msha-controller-operator-history
- **controller_controls_mine:** USG Corporation → Graymont Dolime (OH) Inc.; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** USG Corporation → United States Gypsum Company; 1950-01-01 to 1989-11-07; source msha-controller-operator-history
- **operator_operates_mine:** Gen Lime Group L P → Graymont Dolime (OH) Inc.; 1989-11-08 to 1998-12-06; source msha-controller-operator-history
- **controller_controls_mine:** Gen Lime Corp et al → Graymont Dolime (OH) Inc.; 1989-11-08 to 1998-12-06; source msha-controller-operator-history
- **controller_controls_operator:** Gen Lime Corp et al → Gen Lime Group L P; 1989-11-08 to 1998-12-06; source msha-controller-operator-history
- **operator_operates_mine:** Graymont Dolime (Oh) Inc → Graymont Dolime (OH) Inc.; 1998-12-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Graymont Ltd → Graymont Dolime (OH) Inc.; 1998-12-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Graymont Ltd → Graymont Dolime (Oh) Inc; 1998-12-07 to current/open; source msha-controller-operator-history