These results were above our internal expectations for the current quarter and align with our ability to achieve our 2021 full year earnings guidance range of $3 to $3.30 per share.
The IRP outlines our plans to further transform Minnesota Power's energy supply to 70% renewable by 2030 and to be coal-free and 80% lower carbon by 2035.
All of these plans lay the strong foundation for our vision to provide 100% carbon-free energy to customers by 2050.
While we advance our vision of a carbon-free energy supply by 2050, we will continue to make affordability a priority.
Minnesota Power has completed only three rate cases in the past 25 years, with our last completed rate case back in 2016, five years ago.
The land is not required to maintain operations and has an estimated value of approximately $100 million.
Turning to our second largest business in the ALLETE family, ALLETE Clean Energy with 100% renewable generation is making progress on its multifaceted strategy focused on portfolio optimization, new projects, and plans for expanding service offerings beyond wind to include solar and storage solutions.
Today, ALLETE reported third quarter 2021 earnings of $0.53 per share on net income of $27.6 million.
Earnings in 2020 were $0.78 per share and net income of $40.7 million.
The third quarter results for 2021 did exceed our internal expectations by approximately 25%.
ALLETE's regulated operations segment, which includes Minnesota Power, superior water light and power, and the company's investment in the American Transmission Company recorded net income of $32.9 million compared to $42.4 million in the third quarter of 2020.
In addition, the recording of income tax expense resulted in a negative impact of approximately $5 million or $0.10 per share for the quarter as compared to 2020.
ALLETE Clean Energy recorded a net loss of $800,000 in the third quarter of 2021, compared to net income of $1.1 million in 2020.
As foreshadowed in the second quarter disclosures, ALLETE Clean Energy's wind facilities continued to be impacted by lower wind resources than expected and were 7% below expectations for the quarter.
Our corp and other businesses, which includes BNI Energy and ALLETE properties recorded a third quarter net loss of $4.5 million in 2021, compared to a net loss of $2.8 million in 2020.
I'll now turn to our 2021 earnings guidance, which remains unchanged from our original range of $3 to $3.30 per share.
Consistent with our disclosures in the second quarter, we anticipate our regulated operations segment will be at the higher end of our guidance range of $2.30 to $2.50 per share.
We continue to expect that ALLETE Clean Energy and our corporate other businesses to be at the lower end of our guidance range of $0.70 to $0.80 per share.
This is primarily due to the negative impacts of the extreme winter weather event in the first quarter of 2021 at the Diamond Spring wind energy energy facility of approximately $0.10 per share and lower than expected wind resources and availability throughout 2021.
These negative impacts are partially offset by a 16% after tax gain recorded in the fourth quarter of 2021 for the sale of a portion of the Nemadji Trail Energy Center by South Shore Energy, ALLETE's non-rate regulated Wisconsin subsidiary.
We estimate that approximately $3 million or $0.6 per share is expected to reverse in the fourth quarter.
On November 1st, Minnesota Power filed the retail rate increase request with the MPUC seeking an increase of $108 million in total additional annual revenue.
The filing seeks a return on equity of 10.25% and a 53.81% equity ratio.
Interim rates of $87 million would begin January 1, 2022, with approval by the MPUC.
The rate case assumes taconite production of approximately 34 million tonnes, which is in alignment with the long-term average production levels for taconite.
I'm pleased to report that our trajectory for improved earnings per share growth remains on track and I'm confident in our ability to achieve our long-term annual average earnings-per-share growth objective of within a range of 5% to 7%.
Our planned expansion of our 550 megawatt DC transmission line, participation in the grid North partners initiative, and our increasing investment in the American Transmission Company are clearly of significant strategic value to ALLETE.
In addition to strategic position in initiatives gaining traction at our regulated business, ALLETE Clean Energy is on the verge of completing its construction of Caddo wind project located in Oklahoma, which will serve additional Fortune 500 customers under long-term contracts, and is comfortably on track to be online before the end of this year.
In total, Oklahoma-based Caddo and Diamond Spring projects represent over $800 million of investment and will provide its large C&I customers with over 2.1 million megawatt hours of carbon-free wind generation.
Regarding optimization initiatives underway, the 92 megawatt Red Barn build order transfer project with Wisconsin Public Service Corporation and Madison Gas and Electric will utilize some of our Safe Harbor turbines while expanding our customer base and presence in another geographic region of the country.
An extension of this project and a testimony to our strong relationships with optionality to serve the C&I and/our utility space, the approximately 68 megawatt whitetail development project is advancing with its advanced transmission Q position, landowner relationships, and for either a long-term PPA or build order transfer project.
Speaking of strengthening our development pipeline to leverage is ACE's safe harbor turbines, we continue to advance the 200 megawatt [Inaudible] wind project in North Dakota and are working with state regulators and the Federal Aviation Administration on permitting and siting for this facility.
We are encouraged by North Dakota Governor Burgum's call for the state to be carbon neutral by 2030.
Regarding the up to 120 watt -- megawatt Northern Wind project with Xcel Energy, construction will begin upon receiving permitting approval from the MPUC.
The fact that Minnesota Power serves these customers with 50% renewable energy today directly contributes to the sustainability of their current operations.

Summary:
These results were above our internal expectations for the current quarter and align with our ability to achieve our 2021 full year earnings guidance range of $3 to $3.30 per share.
Today, ALLETE reported third quarter 2021 earnings of $0.53 per share on net income of $27.6 million.