North of Detroit, MI in Oakland County, Michigan
I-75 north to exit 81 north on M-24(Lapeer Rd) towards Lake Orion
South Unit is off of West Scripps, Walden Rd, and Greenshield Rd (hunters use these more)
Slightly south on M-24 from Waldon Rd is the Bald Mountain Lake/Picnic Area entrance
Continue north on M-24, turn right on E. Flint Street, right on Orion Rd, left on Stoney Creek Rd, Left on Harmon rd to find the North Unit Trails
Trail Information: http://www.michigandnr.com/parksandtrails/details.aspx?id=435&type=SPRK
Miscellaneous Information: Oakland County is full of places to run. I have lived in The Lake Orion area most of my life. I started recreational trail running in 2012. I have mountain biked and hiked on the North Unit Trails at Bald Mountain Recreation Area since 1994. They do not have super high elevation but good a few good size hills that make biking challenging and hiking and trail running fun.
The South Unit has trails that go through meadows and around the lake at the Lake/Picnic area.
The North Unit borders the Addison Oaks Oakland County Park which has trails to run on. I camp there and run there when I'm not camping in the warmer months. Orion Oaks is a second favorite place to run in long beautiful meadows. The Paint Creek Trail is down the road from my house off a dirt road. It is an old railroad that had been converted to a well maintained gravel trail that goes from Lake Orion To Rochester (8.9 miles). I have biked this whole distance and ran shorter parts of it. It has a slight grade to the elevation and is a good alternative to running on roads. It butts up to Bald Mountain Recreation Area near Lake Orion.