Investments in certain generation and transmission facilities are jointly-owned with non-affiliated third parties. A proportionate share of jointly-owned facilities is recorded as Property, plant and equipment on the Consolidated Balance Sheets. Our share of the facilities’ expenses is reflected in the appropriate categories of operating expenses in the Consolidated Statements of Income. Each owner of the facility is responsible for financing its investment in the jointly-owned facilities.

At December 31, 2025, our interests in jointly-owned generating facilities and transmission systems were:


	Ownership Interest	Plant in Service		Construction Work in Progress		Less Accumulated Depreciation			Total property, plant and equipment, net
		(in millions)
Wyodak Plant (a)	20%	$	123.5	$	—	$	(80.1	)	$	43.4
Transmission Tie	35%	$	24.5	$	—	$	(8.7	)	$	15.8
Wygen III (b)	52%	$	144.3	$	0.4	$	(31.3	)	$	113.4
Wygen I (c)	76.5%	$	119.4	$	0.5	$	(64.2	)	$	55.7

(a)

In addition to supplying South Dakota Electric with coal for its share of the Wyodak Plant, our mine supplies PacifiCorp’s share of the coal under a separate long-term agreement through December 31, 2026, with an annual renewal option for one-year extensions. This coal supply agreement is collateralized by a mortgage on and a security interest in some of WRDC’s coal reserves.

(b)

South Dakota Electric retains responsibility for plant operations. WRDC supplies fuel to Wygen III for the life of the plant.

(c)

Black Hills Wyoming retains responsibility for plant operations. WRDC supplies fuel to Wygen I for the life of the plant.