Benchmarks are control monuments both vertical and horizontal that have been established by different government entities over the years. These would include benchmarks from NGS, INDOT, IDNR Division of Water, FEMA, Hamilton County Southeastern Utilities, along with benchmarks set by this office on bridge projects and aerial control over the years.

Benchmark Surveys
The Surveyor's Office employs a 2-man Survey Crew year round that researches and field locates these Benchmarks. Data tie sheets for each Benchmark are made and maintained and each Benchmark is GPS located (for reference only). Benchmarks are now available dynamically on the Hamilton County Main Map Room.