Proprietary and Sovereign Public Trust Obligations: From Justinian and Hale to Lamprey and Oswego Lake

Abstract

The public trust doctrine (PTD) has sometimes been mischaracterized as applicable only to state-owned resources. But this “proprietary PTD” is only half of the scope of the PTD, for the doctrine also contains a “sovereign” component. The latter has been recognized for over a century and is not dependent on state ownership of the public trust res. This article examines the evolution of both the proprietary and sovereign PTDs. We first trace the development of the former from Roman and English law through several prominent and recent decisions of the U.S. Supreme Court. We then turn to the lesser-recognized sovereign PTD, which grew out of a largely overlooked, but highly influential, decision of the Minnesota Supreme Court. The article explains the legacy of that case, Lamprey v. Metcalf, which established the now-dominant state-law view that the PTD applies to waterbodies whose beds are privately owned. Unlike the proprietary PTD, which employs the federal test for title navigability, the sovereign usufructuary PTD is not tethered to the federal title test, but is instead the product of state definitions of navigability, which often are much broader than the federal test. The article assesses the implications of widespread judicial recognition of the sovereign PTD as distinct from the proprietary PTD, spotlighting a case pending before the Oregon Supreme Court involving a 400-acre Oregon lake, Oswego Lake, in suburban Portland. But the implications are much broader than that controversy and point to the application of the PTD to all resources of public concern like wildlife, groundwater, and the atmosphere.