[3] The majority of the township is included in the Forest Hills census-designated place, which is used only for statistical purposes.

Ada contains its own post office with the 49301 ZIP Code that serves the majority of the township.

Both the township and village settlement were named for Ada Smith, the daughter of the first postmaster.

[6] Forest Hills is an unincorporated community and census-designated place (CDP) that occupies the majority of the township for statistical purposes.

Forest Hills also occupies a large portion of Cascade Township to the south and is the largest and most-populated CDP in the state.

At the turn of the 19th century, the land that would become Ada was a village of the Grand River Band of Ottawa, led by Nebawnaygezhick.

[5] In 1821, Robinson purchased a former French-Canadian trading post at the junction of the Grand and Thornapple rivers from Madeline La Framboise, on behalf of John Jacob Astor's American Fur Company.

Land north of the Grand River was not available for purchase by European-American settlers until after the United States signed the 1836 Treaty of Washington with regional tribes.

Following the treaty, Robinson purchased hundreds of acres around the mouth of the Thornapple for the Ottawa to continue living on.

Convinced that the land would become valuable, Lyon purchased large tracts from early settlers.

Listed on the National Register of Historic Places, it is one of the few covered bridges that remain standing in the state.