In the midst of the Northwest Indian War, the former surveyor John Adlum's operations as a land agent and his dealings with Cornplanter and other Allegany Senecas helped place a large portion of northwestern Pennsylvania in the hands of wealthy speculators. This article describes the complexity of the postrevolutionary clashes over land between governments, settlers, speculators, and Native Americans. It also demonstrates the critical role of surveyors in land speculation and settlement.