# Relationship history for MSHA mine 4103923

Current hierarchy: **Michael B Doty; Todd  Denton → Quality Stone Company → Lithic Industries**

- 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:** Quality Stone Company, Inc. → Lithic Industries; 1996-09-01 to 2005-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Bobbie G  Simpson et al → Lithic Industries; 1996-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bobbie G  Simpson et al → Quality Stone Company, Inc.; 1996-09-01 to 2005-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Stacie M  Simpson et al → Quality Stone Company, Inc.; 1996-09-01 to 2005-09-14; source msha-controller-operator-history
- **operator_operates_mine:** Quality Stone Company → Lithic Industries; 2005-09-15 to 2017-06-18; source msha-controller-operator-history
- **controller_controls_mine:** Kirk S  Coyne → Lithic Industries; 2005-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kirk S  Coyne → Quality Stone Company; 2005-09-15 to 2017-06-18; source msha-controller-operator-history
- **operator_operates_mine:** Quality Stone Company → Lithic Industries; 2017-06-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Todd  Denton → Lithic Industries; 2017-06-19 to 2022-11-16; source msha-controller-operator-history
- **controller_controls_operator:** Todd  Denton → Quality Stone Company; 2017-06-19 to 2022-11-16; source msha-controller-operator-history
- **controller_controls_mine:** Todd  Denton et al → Lithic Industries; 2022-11-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Todd  Denton et al → Quality Stone Company; 2022-11-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael B Doty et al → Quality Stone Company; 2022-11-17 to current/open; source msha-controller-operator-history