# Relationship history for MSHA mine 3606468

Current hierarchy: **Graymont Ltd → Graymont (PA) Inc. → GRAYMONT (PA) INC. PLEASANT GAP**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Marblehead Lime Company → GRAYMONT (PA) INC. PLEASANT GAP; 1950-01-01 to 1988-01-25; source msha-controller-operator-history
- **controller_controls_mine:** General Dynamics Corp → GRAYMONT (PA) INC. PLEASANT GAP; 1950-01-01 to 1994-05-08; source msha-controller-operator-history
- **controller_controls_operator:** General Dynamics Corp → Marblehead Lime Company; 1950-01-01 to 1988-01-25; source msha-controller-operator-history
- **controller_controls_mine:** Philip J  Senechal → GRAYMONT (PA) INC. PLEASANT GAP; 1986-01-23 to 1998-06-07; source msha-controller-operator-history
- **operator_operates_mine:** Centre Lime & Stone Company Inc → GRAYMONT (PA) INC. PLEASANT GAP; 1988-01-26 to 1995-03-30; source msha-controller-operator-history
- **controller_controls_mine:** Daniel R  Hawbaker  et al → GRAYMONT (PA) INC. PLEASANT GAP; 1988-01-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daniel R  Hawbaker  et al → Centre Lime & Stone Company Inc; 1988-01-26 to 1995-03-30; source msha-controller-operator-history
- **operator_operates_mine:** Bellefonte Lime Company Inc → GRAYMONT (PA) INC. PLEASANT GAP; 1995-03-31 to 1998-06-07; source msha-controller-operator-history
- **controller_controls_operator:** Philip J  Senechal → Bellefonte Lime Company Inc; 1995-03-31 to 1998-06-07; source msha-controller-operator-history
- **operator_operates_mine:** Graymont (PA) Inc. → GRAYMONT (PA) INC. PLEASANT GAP; 1998-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Graymont Ltd → GRAYMONT (PA) INC. PLEASANT GAP; 1998-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Graymont Ltd → Graymont (PA) Inc.; 1998-06-08 to current/open; source msha-controller-operator-history