concurring in the judgment:
I agree with the court that we lack jurisdiction to consider this appeal. I write separately because I cannot join in the majority’s newly-fashioned rule, which would bar the State of California from appealing district court decisions that were *1025clearly erroneous under Swarthout v. Cooke, — U.S. -, 131 S.Ct. 859, 178 L.Ed.2d 732 (2011) (per curiam). In my view, the jurisdictional question here is better resolved on mootness grounds.
I
As an initial matter, the district court clearly erred by ordering the State of California to grant Prellwitz another parole hearing. As the Supreme Court recently reminded us, federal courts may not review state parole decisions for their substance. See Swarthout, 131 S.Ct. at 862-63.
In any event, in my view the district court lacked the authority to order California to conduct a parole hearing because the writ of habeas corpus is limited to either granting or denying a release from custody. Crow v. United States, 186 F.2d 704, 706 (9th Cir.1951). “Habeas lies to enforce the right of personal liberty; when that right is denied and a person confined, the federal court has the power to release him. Indeed, it has no other power; it cannot revise the state court judgment; it can act only on the body of the petitioner.” Fay v. Noia, 372 U.S. 391, 430-31, 83 S.Ct. 822, 9 L.Ed.2d 837 (1963), overruled on other grounds, Wainwright v. Sykes, 433 U.S. 72, 97 S.Ct. 2497, 53 L.Ed.2d 594 (1977); see also Picrin-Peron v. Rison, 930 F.2d 773, 775 (9th Cir.1991) (same).
Thus, if the district court determined that habeas relief were necessary because of a defective parole hearing (which it should not have), the proper remedy was to grant a conditional writ. See Hilton v. Braunskill, 481 U.S. 770, 775, 107 S.Ct. 2113, 95 L.Ed.2d 724 (1987) (“[The Supreme] Court has repeatedly stated that federal courts may delay the release of a successful habeas petitioner in order to provide the State an opportunity to correct the constitutional violation found by the court.”). Then, California could have “take[n] some remedial action” of its own choosing. Harvest v. Castro, 531 F.3d 737, 741 (9th Cir.2008).
II
Regardless of what it should have done, the district court ordered a new parole hearing and that hearing has occurred. Prellwitz has received the relief he sought, and California has held the hearing it did not wish to hold. Thus, this appeal is moot, and we lack jurisdiction. See Foster v. Carson, 347 F.3d 742, 746 (9th Cir.2003) (“Where the activities sought to be enjoined already have occurred, and the appellate courts cannot undo what has already been done, the action is moot, and must be dismissed.” (internal quotation marks omitted)).
By ruling on finality grounds, the majority puts states in the untenable position of being unable to appeal erroneous district court orders. I agree that “[t]o be final, a habeas decision must either den[y] the petition or order[ ] the prisoner released at a specified time.” Op. at 1037 (alterations in original) (internal quotation marks omitted). But before the Supreme Court’s decision in Swarthout, any number of habeas petitions were likely granted in our circuit — without a specific release date — only so that another parole hearing could be held. After Swarthout, it is crystal clear that those decisions were erroneous.
But under the court’s decision today, the government could rarely — if ever — appeal such an order. If the state obeys the order and holds the hearing, the appeal (like this one) is moot. If the state does not wish to obey the order, it would have no guarantee of immediate review under the rule announced today. Nor could the state ignore the order in the hope of later challenging it in an enforcement proceeding. See Walker v. City of Birmingham, 388 U.S. 307, 87 S.Ct. 1824, 18 L.Ed.2d *10261210 (1967); In re Establishment Inspection of Hem Iron Works, Inc., 881 F.2d 722, 725 (9th Cir.1989) (“In brief, the collateral bar rule permits a judicial order to be enforced through criminal contempt even though the underlying decision may be incorrect and even unconstitutional.”).
Moreover, even application of the seemingly bright-line rule proposed by the majority would be difficult in practice. As in this ease, it is often difficult to tell whether a district court is actually granting a writ of habeas corpus. See Alexander v. U.S. Parole Comm’n, 514 F.3d 1083, 1087 (10th Cir.2008) (“Unfortunately, not all orders state clearly whether release has been granted or .denied.”). Thus, closer inspection would be needed on a case-by-case basis to determine whether an ambiguous order is “the functional equivalent of a conditional release order.” Id. at 1089. I think it inappropriate for us to be undertaking such an inquiry.
Ill
Given these difficulties with the majority’s new rule, I cannot join in its opinion. I do, however, agree that we do not have jurisdiction over this appeal. Accordingly, I would dismiss for mootness and vacate the judgment of the district court. See Burke v. Barnes, 479 U.S. 361, 365, 107 S.Ct. 734, 93 L.Ed.2d 732 (1987).