# Relationship history for MSHA mine 4800017

Current hierarchy: **Chad  Fladland; Angela  Fladland → TONGUE RIVER STONE INC → TONGUE RIVER STONE 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:** Guernsey Stone Company → TONGUE RIVER STONE INC; 1950-01-01 to 1986-04-13; source msha-controller-operator-history
- **controller_controls_mine:** Peter Kiewit Sons' Inc → TONGUE RIVER STONE INC; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peter Kiewit Sons' Inc → Guernsey Stone Company; 1950-01-01 to 1986-04-13; source msha-controller-operator-history
- **operator_operates_mine:** Tongue River Stone Inc → TONGUE RIVER STONE INC; 1986-04-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Nancy J  Nickelson et al → TONGUE RIVER STONE INC; 1986-04-14 to 2014-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Nancy J  Nickelson et al → Tongue River Stone Inc; 1986-04-14 to 2014-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Blaine R Phillips → TONGUE RIVER STONE INC; 2015-01-01 to 2024-01-01; source msha-controller-operator-history
- **controller_controls_operator:** Blaine R Phillips → Tongue River Stone Inc; 2015-01-01 to 2024-01-01; source msha-controller-operator-history
- **controller_controls_mine:** Chad  Fladland et al → TONGUE RIVER STONE INC; 2024-01-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chad  Fladland et al → Tongue River Stone Inc; 2024-01-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Angela  Fladland et al → Tongue River Stone Inc; 2024-01-02 to current/open; source msha-controller-operator-history