Blake’s contention that the prison’s grievance process was not in fact available to him warrants further consideration below. Pp. 8–14.

(a) Blake’s suit may yet be viable. The PLRA contains its own, textual exception to mandatory exhaustion. Under §1997e(a), an inmate’s obligation to exhaust hinges on the “availab[ility]” of administrative remedies. A prisoner is thus required to exhaust only those grievance procedures that are “capable of use” to obtain “some relief for the action complained of.” Booth, 532 U. S., at 738.
     As relevant here, there are three kinds of circumstances in which an administrative remedy, although officially on the books, is not capable of use to obtain relief. First, an administrative procedure is unavailable when it operates as a simple dead end—with officers unable or consistently unwilling to provide any relief to aggrieved in- Cite as: 578 U. S. ____ (2016) 3 Syllabus mates. Next, an administrative scheme might be so opaque that it becomes, practically speaking, incapable of use—i.e., some mechanism exists to provide relief, but no ordinary prisoner can navigate it. And finally, a grievance process is rendered unavailable when prison administrators thwart inmates from taking advantage of it through machination, misrepresentation, or intimidation. Pp. 8–11.

(b) The facts of this case raise questions about whether, given these principles, Blake had an “available” administrative remedy to exhaust. Ross’s exhaustion defense rests on Blake’s failure to seek relief through Maryland’s Administrative Remedy Procedure (ARP) process, which begins with a grievance to the warden. That process is the standard method for addressing inmate complaints in the State’s prisons. But Maryland separately maintains the IIU to look into charges of prison staff misconduct, and the IIU did just that here. Blake urged in the courts below that once the IIU commences such an inquiry, a prisoner cannot obtain relief through the ARP process. And in this Court, the parties have lodged additional materials relating to the interaction between the IIU and the ARP. Both sides’ submissions, although scattershot and in need of further review, lend some support to Blake’s account.        

​Blake’s filings include many administrative dispositions indicating that Maryland wardens routinely dismiss ARP grievances as procedurally improper when parallel IIU investigations are pending. In addition, Blake has submitted briefs of the Maryland attorney general specifically recognizing that administrative practice. And Ross’s own submissions offer some confirmation of Blake’s view: Ross does not identify a single case in which a warden considered the merits of an ARP grievance while an IIU inquiry was underway. On remand, the Fourth Circuit should perform a thorough review of such materials, and then address whether the remedies Blake did not exhaust were “available” under the legal principles set out here. Pp. 11–14.