Document ID: ./input/supremecourt_opinions/opinions/22pdf/21-1484_aplc.pdf
Page Number: 32

Cite as:  599 U. S. ____ (2023) 

11 

GORSUCH, J., dissenting 

Navajo may have in the river.  Id., at 110.  The Department 
posited  that  figuring  that  out  would  be  a  “somewhat 
lengthy process,” one that had “yet to be initiated.”  Ibid. 

Unwilling  to  wait  indefinitely,  the  Navajo  eventually
filed this suit.  In it, the Navajo sought “injunctive and de-
claratory relief to compel the Federal Defendants to deter-
mine the water required to meet the needs of the Nation’s 
lands in Arizona and devise a plan to meet those needs to
fulfill the promise of the United States to make the Nation’s
Reservation  lands  a  permanent  homeland  for  the  Navajo
people.”  Id.,  at  86.  In  other  words,  the  Tribe  asked  the 
United States to assess what water rights it holds in trust
on the Tribe’s behalf pursuant to the Treaty of 1868.  Tr. of 
Oral Arg. 71–72.  And if it turns out the United States has 
misappropriated  those  water  rights,  the  Tribe  wants  the 
federal  government  to  come  up  with  a  plan  to  set  things
right. 

II 

With a view of this history, the proper outcome of today’s 
case follows directly.  The Treaty of 1868 promises the Nav-
ajo a “permanent home.”  Treaty Between the United States 
of America and the Navajo Tribe of Indians, June 1, 1868, 
Art.  XIII,  15  Stat.  671  (ratified  Aug.  12,  1868)  (Treaty  of 
1868).  That promise—read in conjunction with other pro-
visions  in  the  Treaty,  the  history  surrounding  its  enact-
ment, and background principles of Indian law—secures for 
the Navajo some measure of water rights.  Yet even today 
the extent of those water rights remains unadjudicated and 
therefore  unknown.    What  is  known  is  that  the  United 
States holds some of the Tribe’s water rights in trust.  And 
it exercises control over many possible sources of water in
which the Tribe may have rights, including the mainstream
of the Colorado River.  Accordingly, the government owes
the Tribe a duty to manage the water it holds for the Tribe
in a legally responsible manner.  In this lawsuit, the Navajo