The counties that are contiguous with Ottawa County are:
 Muskegon, Kent and Allegan. 
(Oceana County was formed in 1831 from Ottawa County)

Ottawa County was "created" in 1831, organized in 1837,  parent county/ies being 
 Michilimackinac (unorganized land) & Kent


Muskegon County came into being in 1859, when Ottawa County was divided.

Kent County was established about 1836.

Allegan County was created abt. 1831. Part of the City of Holland is in Allegan Co. today.