REGULATORY MATTERS (Tables)

6 Months Ended

Jun. 30, 2025

Regulated Operations [Abstract]

Schedule of Regulatory Assets and Liabilities

The recovery, refund or credit to rates for these regulatory assets and liabilities will occur over the periods either specified by the applicable regulatory authority or over the corresponding period related to the asset or liability.

NOTE 2. REGULATORY MATTERS (Continued)

Regulatory Assets and Liabilities	June 30, 2025	December 31, 2024
Millions
Current Regulatory Assets (a)
Fuel Adjustment Clause	$3.2	—
Other	1.6	$1.6
Total Current Regulatory Assets	$4.8	$1.6
Non-Current Regulatory Assets
Defined Benefit Pension and Other Postretirement Benefit Plans	$197.2	$200.3
Income Taxes	81.4	84.9
Asset Retirement Obligations	43.1	41.0
Taconite Harbor	10.5	17.3
Manufactured Gas Plant	10.8	11.6
Cost Recovery Riders	13.9	5.5
PPACA Income Tax Deferral	3.6	3.7
Fuel Adjustment Clause	0.7	4.5
Other	1.8	2.9
Total Non-Current Regulatory Assets	$363.0	$371.7
Current Regulatory Liabilities (b)
Provision for Interim Rate Refund	—	$23.0
Fuel Adjustment Clause	$2.2	7.2
Other	1.1	1.3
Total Current Regulatory Liabilities	$3.3	$31.5
Non-Current Regulatory Liabilities
Income Taxes	$283.2	$292.7
Wholesale and Retail Contra AFUDC	79.4	77.6
Plant Removal Obligations	78.2	74.2
Non-Jurisdictional Land Sales	74.8	59.7
Defined Benefit Pension and Other Postretirement Benefit Plans	37.2	40.7
Investment Tax Credits	17.4	17.8
Boswell Units 1 and 2 Net Plant and Equipment	6.7	6.7
Fuel Adjustment Clause	5.7	0.6
Other	4.1	0.5
Total Non-Current Regulatory Liabilities	$586.7	$570.5

(a)Current regulatory assets are presented within Prepayments and Other on the Consolidated Balance Sheet.

(b)Current regulatory liabilities are presented within Other Current Liabilities on the Consolidated Balance Sheet.