I don't know what the trials are called, but there are some good rides in that area. Call Breakaway Bicycles in Muskegon. They will be able to help you, if you can stop by the store they probably have trail maps.
If you are mountain biking then you will want to go to Owaissipe off Russell Road. It just opened back up and is supposed to be awesome.
Otherwise Michillinda Rd is good although flat. Check out the Duck Lake TT route or the North Muskegon triathlon route for some good areas. It is pretty rural between whitehall and north muskegon with lots of good options. There is also the pathway that goes from Montague to Cadillac I believe.