Area Highlights:
Bay City, Michigan
Bay City is close to Lake Huron, specifically on Saginaw Bay, with various parks next to Lake Huron featuring wetlands and bird watching. The reception itself is right next to a park alongside the Saginaw River which feeds into Saginaw Bay.
Bay City is known for its collection of antique stores and fairly vibrant downtown with quite a few restaurants and bars north a few blocks from the Doubletree. There are several interesting antique shops along Water Street about 4 blocks north of the hotel.
A bit south of the Doubletree along the river is an area called Uptown with several upscale restaurants, a highly rated wine bar called Prost and a gourmet ice cream parlor.
Saginaw, Michigan
Saginaw Children's Zoo is a relaxing place for family time. In addition to its child size animals, it features a children's train ride around the zoo and a carousel.
Mid-Michigan Children's Museum features interactive exhibits with an emphasis on science.
Midland Michigan
Dow Gardens: 110 acres of beautiful gardens with 20,000 annual varieties. This is quite impressive and beautiful.
Admission to Dow Gardens includes the Nation's longest Canopy Tree Walk
The Tridge: Also nearby in Midland is a very unique 3-legged wooden footbridge where two rivers meet, called "The Tridge". There are walking paths, a dog park and a frisbee golf course near the Tridge.
A bit farther away to the south, but maybe a worthwhile stop on your way to Saginaw/Bay City. This small Bavarian style town is the home of interesting small shops, quite good German food, water parks, as well as the extensive Bronner's CHRISTmas Wonderland .
Farther Afield
In case you decide to spend extra days e.g. in the Detroit area or elsewhere in Michigan or the Midwest, some additional interesting places are: Greenfield Village and the Henry Ford Museum (Dearborn, near Detroit), Detroit Institute of Arts (with famous Detroit Industry murals of Diego Rivera), Comerica Park (where Detroit Tigers play), Greektown (good food in downtown Detroit), and Ann Arbor (home of University of Michigan, also near Detroit airport). A bit farther away are: Cedar Point Amusement Park (Sandusky, Ohio, one of the very best roller coaster parks in the world), Traverse City (several hours drive but popular and includes the Sleeping Bear Dunes National Lakeshore), and assorted towns along the shores of Lake Huron and Lake Michigan.
There are often better airfares mid-week, if you do decide to spend extra days in the area.