Tinkers Creek is the largest tributary to the Cuyahoga River and flows through 19 different political jurisdictions and 4 counties. The headwaters of this system begin near State Route 43 in Sugar Bush Knolls. This area was glaciated thousands of years ago, resulting in geologic features that are specific to the watershed. Northern gravel deposits rich in magnesium and calcium were left as the Wisconsinian glacier retreated, producing soils with a high alkaline content. Cold water springs began to bubble up from the ground and became trapped beneath the clay and silt deposit, resulting in fen conditions. Herrick Fen is located at the very upper stretches of Tinkers Creek and is protected within the Tinkers Creek State Nature Preserve.

The unique soils have caused northern coniferous species such as tamarack to colonize; the only reproducing tamarack communities in Ohio are located within the watershed. Cinquetail-sedge fen supporting bayberry is listed on the state's endangered species list, along with 11 other species found exclusively in this preserve. Within the corporate boundaries of Streetsboro, thousands of acres of high class wetlands still exist. These wetlands were also a product of the glaciation period. They perform vital functions for the community by reducing flooding, providing biological habitat, and reducing the mosquito population in the summer months.