City of Lake Saint Louis, Missouri, Plaintiff/Respondent v. City of O'Fallon, Missouri

Introduction

City of O’Fallon, Missouri (O’Fallon) appeals from the circuit court’s entry of summary judgment in favor of City of Lake Saint Louis, Missouri (Lake St. Louis) on Lake St. Louis’s petition seeking a declaratory judgment establishing Lake St. Louis’s northern boundary. We affirm.

Factual and Procedural Background

This case involves a dispute over the annexation of land. The area in dispute is approximately depicted in the map below by the cross-hatched area:

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O’Fallon lies to the north of disputed property and Lake St. Louis to the south; the municipalities have asserted…