ARMSTRONG, J.

¶1 Citizens for Responsible Wildlife Management (Citizens) and 12 other organizations challenge Initiatives 655 and 713 (the Initiatives), which prohibit various hunting and trapping practices. Citizens argues that the Initiatives violate the State's duty to control and manage wildlife for the public's benefit (public trust doctrine). Assuming without deciding that the public trust doctrine applies, Citizens' challenge fails because the State did not relinquish control over the public's interest in the State's natural resources. Accordingly, we affirm summary judgment in favor of the State.

FACTS

¶2 In November 1996, Washington voters approved Initiative 655, which made it unlawful to hunt black bear with the aid of bait or to hunt black bear, cougar, bobcat, or lynx with the aid of dogs. Initiative 655 is codified at RCW 77.15.245. In November 2000, Washington voters approved Initiative 713, which prohibits the use of body-gripping traps and other devices to capture animals and bans the use of two poisons, sodium fluoroacetate and sodium cyanide. Initiative 713 is codified at RCW 77.15.192, .194, .196, and .198.

¶3 Citizens sued the State to enjoin implementation and enforcement of the Initiatives. Citizens alleged that the Initiatives violate the public trust doctrine. Both parties moved for summary judgment. The trial court granted the State's motion, ruling that the Initiatives do not violate the public trust doctrine.

ANALYSIS I. Summary Judgment Standard

¶4 When reviewing a summary judgment order, we engage in the same inquiry as the trial court. Wilson v. Steinbach, 98 Wn.2d 434, 437, 656 P.2d 1030 (1982). Summary judgment is appropriate only if the pleadings, affidavits, depositions, and admissions on file demonstrate the absence of any genuine issues of material fact and that the moving party is entitled to judgment as a matter of law. CR 56(c).

II. The Scope of Washington's Public Trust Doctrine

¶5 Citizens argues that the public trust doctrine applies to upland wildlife. And, according to Citizens, I-655 and I-713 impermissibly relinquish the State's control over renewable natural resources and wildlife.

¶6 The public trust doctrine concerns the public's right to navigation and the incidental rights of fishing, boating, swimming, waterskiing, and other related recreational uses of public waters. Caminiti v. Boyle, 107 Wn.2d 662, 669, 732 P.2d 989 (1987) (quoting Wilbour v. Gallagher, 77 Wn.2d 306, 316, 462 P.2d 232 (1969)).

¶7 Title to animals ferae naturae belongs to the State in its sovereign capacity and the State holds this title in trust for the people's use and benefit. Graves v. Dunlap, 87 Wash. 648, 651, 152 P. 532 (1915). As the Washington Supreme Court explained in Cawsey v. Brickey, 82 Wash. 653, 656, 144 P. 938 (1914):

Under the common law of England all property right in animals ferae naturae was in the sovereign for the use and benefit of the people. The killing, taking and use of game was subject to absolute governmental control for the common good. This absolute power to control and regulate was vested in the colonial governments as a part of the common law. It passed with the title to game to the several states as an incident of their sovereignty and was retained by the states for the use and benefit of the people of the states, subject only to any applicable provisions of the Federal constitution.

¶8 No Washington case has applied the public trust doctrine to terrestrial wildlife or resources. See, e.g., State v. Longshore, 141 Wn.2d 414, 5 P.3d 1256 (2000) (second degree theft conviction for stealing naturally occurring clams on private tidelands); R.D. Merrill Co. v. State, 137 Wn.2d 118, 969 P.2d 458 (1999) (water rights); Weden v. San Juan County, 135 Wn.2d 678, 958 P.2d 273 (1998) (county ordinance banning personal watercraft on all marine waters and one lake); Rettkowski v. Dep't of Ecology, 122 Wn.2d 219, 858 P.2d 232 (1993) (public trust doctrine not germane to issues concerning water rights to nonnavigable stream); Caminiti, 107 Wn.2d 662 at 663 (private recreational docks on state-owned tidelands and shorelands). But we need not decide whether the public trust doctrine applies here because, even if it does, Citizens' challenge fails.

III. The Public Trust Doctrine and the Challenged Initiatives

¶9 A statute enacted through the initiative process is presumed constitutional and the party challenging it bears the burden of proving it unconstitutional beyond a reasonable doubt. Amalgamated Transit Union Local 587 v. State, 142 Wn.2d 183, 205, 11 P.3d 762 (2000). Nonetheless, courts review legislation under the public trust doctrine with a heightened degree of judicial scrutiny, as if measuring the legislation against constitutional protections. Weden, 135 Wn.2d at 698 (quoting Ralph W. Johnson, et al., The Public Trust Doctrine and Coastal Zone Management in Washington State, 67 WASH. L. REV. 521, 525-27 (1992)).

¶10 The public trust doctrine developed out of the public's need for access to navigable waters. Caminiti, 107 Wn.2d at 669-70; Orion Corp. v. State, 109 Wn.2d 621, 640, 747 P.2d 1062 (1987). This policy is expressed, in part, in article XVII, section 1 of the Washington Constitution, which asserts the state's ownership of the beds and shores of the state's navigable waters. Rettkowski, 122 Wn.2d at 232.

¶11 Washington's ownership of tidelands and shorelands has two parts. Caminiti, 107 Wn.2d at 668. The jus privatum is the private property interest under which the state may convey title to these lands. Caminiti, 107 Wn.2d at 668. But at issue here is the jus publicum, or public authority interest. Caminiti, 107 Wn.2d at 668.

¶12 The public trust doctrine protects "`public ownership interests in certain uses of navigable waters and underlying lands, including navigation, commerce, fisheries, recreation, and environmental quality.'" Weden, 135 Wn.2d at 698 (quoting Johnson, supra, at 524). In other words, the public trust doctrine grants the state dominion and sovereignty over these lands to hold in trust for the public. Caminiti, 107 Wn.2d at 669. And this duty devolves on the state, not on a particular agency. Rettkowski, 122 Wn.2d at 232.

¶13 When deciding if challenged legislation violates the public trust doctrine, we ask: (1) whether the state has given up its right of control over the jus publicum; (2) if so, whether the state (a) has promoted the public's interest in the jus publicum, or (b) has not substantially impaired it. Caminiti, 107 Wn.2d at 670 (citing Ill. Cent. R.R. v. Illinois, 146 U.S. 387, 453, 13 S. Ct. 110, 36 L. Ed. 1018 (1892)). Individual states have the authority to define the limits of the lands held in public trust and to recognize the private rights in these lands as they see fit. Longshore, 141 Wn.2d at 428 (looking " solely to Washington law to determine" the scope of the public trust doctrine).

¶14 "An exercise of the initiative power is an exercise of the reserved power of the people to legislate." Amalgamated Transit, 142 Wn.2d at 204 (citing State ex rel. Heavey v. Murphy, 138 Wn.2d 800, 808, 982 P.2d 611 (1999)). And when the voters approve an initiative, they exercise the same power of sovereignty as the legislature does when it enacts a statute. Amalgamated Transit, 142 Wn.2d at 204 (citing Wash. Fed'n of State Employees v. State, 127 Wn.2d 544, 556, 901 P.2d 1028 (1995)).

¶15 In Caminiti, the Supreme Court held that RCW 79.90.105 did not violate the public trust doctrine; the statute allows owners of residential property abutting state-owned tidelands and shorelands to build recreational docks on these lands without paying the state. Caminiti, 107 Wn.2d at 665-66. The court concluded that the legislature had given up relatively little right of control over the jus publicum. For example, the challenged statute did not apply to harbor areas in navigable waters in front of and one mile on either side of cities bordering navigable waters. And the statute limited dock use to private recreational purposes, specifically authorized the Department of Natural Resources to regulate the docks, and subjected the docks to local regulations. Finally, the court identified the legislature's ability to repeal the statute as the "ultimate state control." Caminiti, 107 Wn.2d at 672-73.

¶16 In Weden, the court held that a San Juan County ordinance banning the use of motorized personal watercraft on all marine waters and one lake did not violate the public trust doctrine because the County had not given up control over its waters. Weden, 135 Wn.2d at 699. The court found that while the ordinance prohibited a particular form of recreation, the waters were open to the entire public, including personal watercraft owners who use other recreational methods. And the court noted that "it would be an odd use of the public trust doctrine to sanction an activity that actually harms and damages the waters and wildlife of this state." Weden, 135 Wn.2d at 699-700.

¶17 Here, the State and intervenors identify numerous ways in which the State maintains control over wildlife. For example, the legislature and the citizens of Washington retain the power to amend or repeal the statutes codifying I-655 and I-713 under Washington Constitution article II, section 41, and article II, section 1, respectively. In fact, the legislature amended I-655 in 2000 to allow the Fish and Wildlife Commission to authorize using dogs to address public safety concerns related to cougars. Engrossed Substitute S.B. 5001, 56th Leg., Reg. Sess. (Wash. 2000). And the commission responded to the legislature's amendment by promulgating regulations governing public safety cougar removals. WAC 232-12-243.

¶18 The Initiatives' bans are also subject to important exceptions. State employees or agents acting in their official capacity may kill black bears with the aid of bait or hunt black bear, cougar, and certain other animals with dogs to protect livestock, domestic animals, private property, or public safety. RCW 77.15.245(1)(a), (2)(a). And I-655 does not prohibit using bear feeding stations to prevent damage to commercial timberland. RCW 77.15.245(1)(b). Public agencies, universities, and scientific or educational institutions with a properly issued permit or memorandum of understanding may use bait to attract black bear for scientific purposes. RCW 77.15.245(1)(c).

¶19 Initiative 713 excepts "[c]age and box traps, suit-case-type live beaver traps, and common rat and mouse traps" from its definition of "body-gripping trap." RCW 77.15.192(2). And I-713 allows the use of three types of traps with a properly granted special permit. RCW 77.15.194(4). Initiative 713 also allows the Washington Department of Fish and Wildlife (WDFW) director to grant permits to department employees or agents to use otherwise banned traps where using such traps is the only practical means of protecting threatened or endangered species. RCW 77.15.194(4)(c). A similar provision applies to the United States Fish and Wildlife Service's use of traps to protect threatened or endangered species listed in the federal Endangered Species Act of 1973. RCW 77.15.194(5).

¶20 In addition, WDFW has authority to adopt rules to "`fill in the gaps'" in legislation if necessary to implement the general statutory scheme. Armstrong v. State, 91 Wn. App. 530, 538, 958 P.2d 1010 (1998) (quoting Hama Hama Co. v. Shorelines Hearings Bd., 85 Wn.2d 441, 448, 536 P.2d 157 (1975)). Here, WDFW has promulgated rules implementing both initiatives. See, e.g., WAC 232-12-001, -071, -141, -142 (regulations regarding I-713); WAC 232-12-243 (public safety cougar removals under I-655).

¶21 Moreover, WDFW has management tools other than those the challenged initiatives proscribe. WDFW retains control over wildlife by setting hunting seasons and by regulating hunting methods, areas of the hunt, and the sex and age of the animals that may be taken. See, e.g., WAC 232-28-272 (Black Bear and Cougar Hunting Season and Regulations), -351 (Deer Season and Limits), -352 (Elk Season and Limits).

¶22 Finally, other statutes restrict the public's ability to hunt wildlife. See, e.g., RCW 77.15.450 (class C felony to hunt big game with aid of spotlight while in possession of a firearm or bow and arrow), .675 (unlawful to hunt while under influence of intoxicating liquors or drugs).

¶23 Citizens also argues that because the legislature has expressly delegated responsibility for the state's natural resources to state agencies, citizen initiatives and referenda that interfere with these duties are precluded. But the cases Citizens cites do not stand for such a broad proposition. Rather, the cited cases concern legislative grants of authority to cities and counties and hold that initiative or referendum rights do not exist where the legislature has delegated power to a city or county legislative authority. See, e.g., Snohomish County v. Anderson, 123 Wn.2d 151, 156, 868 P.2d 116 (1994); Citizens for Financially Responsible Gov't v. City of Spokane, 99 Wn.2d 339, 345, 662 P.2d 845 (1983); Leonard v. City of Bothell, 87 Wn.2d 847, 852-54, 557 P.2d 1306 (1976); Neils v. City of Seattle, 185 Wash. 269, 282-83, 53 P.2d 848 (1936); Save Our State Park v. Bd. of Clallam County Comm'rs, 74 Wn. App. 637, 647-48, 875 P.2d 673 (1994); Lince v. City of Bremerton, 25 Wn. App. 309, 312-13, 607 P.2d 329 (1980). Here, the Initiatives do not interfere with a state grant of authority to a local government.

¶24 We conclude that in passing I-655 and I-713, Washington voters did not give up control over the state's natural resources in violation of the public trust doctrine. Rather, the Initiatives as implemented provide specific restrictions on techniques for hunting and trapping certain wild animals. If anything, this is an assumption of greater rather than lesser control. Accordingly, we affirm the summary judgment in favor of the State.

¶25 Affirmed.

SEINFELD, J. Pro Tem., concurs.