Snapshot: In October 2011, the Indigenous Osage Nation and the US initiated litigation against Osage Wind and Enel in Oklahoma, USA, alleging unauthorised mining regarding a wind farm project. Following an initial dismissal, a 2017 Tenth Circuit Court of Appeals decision reversed the ruling, affirming the occurrence of mining activities. In December 2023, the District Court granted summary judgment, ordered the removal of 84 wind turbines, and scheduled a trial to determine damages. The case is ongoing.

Factual background

Beginning in 2010, Osage Wind, Enel Kansas, and Enel Green Power leased approximately 8,400 acres in Osage County, Oklahoma, to construct a commercial wind farm. The project encompassed the installation of 84 wind turbines, along with associated infrastructure such as underground electrical lines, an overhead transmission line, meteorological towers, and access roads. Reinforced concrete foundations were utilised to secure the wind towers.

Legal argument

In 1906, the Osage Nation's reservation in Osage County underwent a division of surface and mineral estates through the Osage Act. This granted the Osage Nation the authority, subject to approval from the Secretary of the Interior, to issue leases for mineral extraction. According to regulatory oversight outlined in 25 C.F.R. Part 214, no mining activities are permitted on a tract of land until an approved lease is in place (Section 214.7).

The wind farm project, involving excavating and installing turbines and cables, resulted in the removal of sand, soil, and rock, causing irreversible alterations to the mineral estate. The companies were accused of failing to secure the necessary approval and engaging in unauthorised mining activities. Both the US and the Osage Nation argue that these activities constitute trespass, ongoing trespass, and conversion. In addition, some Osage Nation members opposed the project because of the fear of damaging the environment, its potential encroachment on sacred burial sites, as well as the turbines’ deadly impact on eagles, that are sacred birds.

The legal claims set forth by the US encompass five counts, mirrored by the Osage Mineral Council, except for an additional conversion claim. The violations are anchored in the infringement of 25 C.F.R. § 211 and 25 C.F.R. § 214, including trespass, continuing trespass, and conversion.

Legal proceeding

In October 2011, the Osage Nation Indigenous community filed a lawsuit before the District Court in Oklahoma against Wind Capital Group to halt the project, asserting that it unlawfully deprived them of mineral estate access.

On 20 December 2011, the case was dismissed on its merits.

On 21 November 2014, the US, acting as a trustee for the Osage Mineral Estate, initiated legal action against Osage Wind, Enel Kansas and Enel Green Power North America in front of the District Court. The lawsuit sought a declaratory judgment that the Defendants engaged in unauthorised mining and excavation without obtaining a lease.

The companies, in turn, moved for summary judgment on the claims because the facts of the case were undisputed and to avoid going to full trial.

On 30 September 2015, the District Court ruled in favour of the companies, stating that their activities did not amount to mining and, therefore, no lease was required.

The US did not appeal the District Court's decision, but the Osage Minerals Council, acting on behalf of the Osage Nation, did.

On 18 September 2017, the Tenth Circuit Court of Appeals reversed the decision, determining that mining activities had indeed taken place, requiring a lease under regulatory provisions. The case was referred back to the district court for further proceedings consistent with the decision.

The US and the Osage Mineral Council asked for summary judgment. The Plaintiffs argued for violations of 25 C.F.R. §211, 214, trespass, continuing trespass and conversion and sought injunctive relief.

On 20 December 2023, the District Court approved all claims and found summary judgment fitting, granting monetary damages for trespass and conversion to the plaintiffs. It stated that "permitting the wind turbines to remain in place will cause the Osage Nation to suffer irreparable harm and its sovereignty and authority to manage the mineral estate. This cannot be remedied by a payment of money damages." It ordered the wind turbines to be removed. Additionally, the District Court ordered a trial to be scheduled on the issue of damages.

In January 2024, Enel Energy announced that it plans to appeal the court decision.

In December 2024, Enel Energy was ordered to pay damages.

In March 2025 the removal of the wind turbines was temporarily paused during Enel's appeal process.

News Items

• Removal of Osage County wind farm paused, OPMX , 7 March 2025
• Osage Nation seeks damages from Enel over wind turbines on tribal land, Financial Times, 27 Jan 2024
• Oklahoma district court orders removal of operating Osage Wind Farm turbines to protect Osage Nation’s sovereignty, Politico, 4 Jan 2024
• USA: Osage Nation's mineral estate won't be harmed by wind farm project, federal judge rules, Osage News, 16 Dec 2011

Court Documents

• District Court Decision, 20 Dec 2023
• Tenth Circuit Court of Appeals Decision, 18 Sep 2017
• District Court Decision, 22 Nov 2011