Note most of these all require passes to park (metropark vs. state park)
Potowami (Poto) - http://www.michigandnr.com/parksandtrails/Details.aspx?id=229&type=SPTR#map-tab Probably the most popular place to run trails, but also mountain bike in the area. It’s ~25 mins from Westside of Ann Arbor and is rather hilly/technical for the area.
Island Lake - http://www.michigandnr.com/parksandtrails/Details.aspx?id=462&type=SPRK Mostly flat like a pancake with very few hills, this is another popular spot to enjoy the woods, but without the hills to punish. It’s also an incredibly popular MTB spot for beginners.
Kensington - http://www.metroparks.com/parks/kensington-metropark/ Connected to Island Lake, this is a paved trail typically used by road bikers and road runners looking to enjoy a long stretch of car free area. It circles a large lake.
Brighton Rec Center - http://www.michigandnr.com/parksandtrails/Details.aspx?id=438&type=SPRK Another popular MTB area, the trails are broken into difficulty, all looping back to central areas. They are very runnable and middle of the road to ease tech wise for the area.
Waterloo-Pinckney - http://www.michigandnr.com/Publications/PDFS/RecreationCamping/Waterloo_pinckney_trail_waterloo.pdf Point-to-point 36 miles of rugged terrain. Bikes aren’t allowed out here, but it’s a popular horse trail when the weather is cooperative. This can lead to a unique trail consistency. The trail itself varies significantly from hilly forest, to fields, to a river crossing.
We will typically jump in at the Eddy Discovery Center and run and out and back in one direction.
Highland Rec Area - https://www.mtbproject.com/trail/7000974/highland-recreation-a-b-c-d-loops Now we’re getting way out there. This trail is the most technical one in the area and is open to MTB. Since it’s rather technical, you rarely see too many folks out there — it’s an unforgiving 16+ miles of switch backs. The park is used, but not as well used as the others listed above. There are many ways to take short cuts, as each loop is taken off of a main path.
Pontiac Lake - http://www.michigandnr.com/Publications/PDFS/RecreationCamping/pontiac-lake-bike-trail.pdf Now we’re getting way, way, way out there. This is the furtherest I’ll typically travel and perhaps only once a year. This 10 mile loop isn’t really worth going unless you’re going to double it. It features one long climb which looks out over the surrounding area.
Bigger trails, or combinable trail areas are as follows. Since Ann Arbor has ordinances requiring all residential areas have a park within 1 mile, there are tons of smaller parks that can be strung together.
Bird Hills/Kuebler Langford/Barton Nature Area/Bandemer - http://www.a2gov.org/departments/Parks-Recreation/parks-places/Pages/BirdHills.aspx These parks can all be combined together without running on the road for very long. They are the largest and most popular in the area.
The Arb/Gallup Park - https://www.lsa.umich.edu/mbg/see/nicholsarboretum.asp These are two popular parks near UM which can be strung together or done separately. The Arb is “famous” for the hill workouts one can do.
Leslie Science Center Area - http://www.lesliesnc.org/ In the north east area there are a number of parks that be strung together that touch the Leslie Science Center.
Ann Arbor Track Club - http://aatrackclub.org/ - A fun, friendly group. I’ve met a lot of folks I still run with regularly from here. There’s a big mix of ages.
Run Ann Arbor (through Ann Arbor Running Company) - http://run-annarbor.com/ - I’ve run with these folks a bunch due to their close association with Ann Arbor Running Company. The route is different each time and is a good way to explore and learn the area. The age range is large here as well.
PR Fitness - https://www.facebook.com/prrunclub/ There are a number of fast folks who run here and the routes are pretty decent, often looping far up north of the city into the Barton Hills Country Club area, or far down south towards Gallup Park.
These places exist as well, but I haven’t had enough time in my life to participate:
B2B Trail - http://www.ewashtenaw.org/government/departments/parks_recreation/greenways/maps/detailed-overview-maps This is easily the most beautiful place to run in Ann Arbor if you like the water. The trail mirrors the Huron River for almost the entire time while cutting through a number of parks.
@i'm involved w/Ann Arbor Track Club and Run Ann Arbor (through being a team Ann Arbor Track Club member and Ann Arbor Running Company Team Member)