The Erie Canal Trail - From Albany to Buffalo! There are a few great local stretches of the canal that are great for bikes, runs, walking the dog and more! The nearest access from the City is at Butternut Creek Aqueduct.
Onondaga Lake Parkway - This is a family-friendly and multi-use parkway near the lake where you dont have to worry about traffic and is mainly flat, mostly paved, and is pretty well maintained in the winter. The trail is approximately 20 miles. Here's what the park says about itself. "Four Great Trails at Onondaga Lake Park! Whether it's in-line skating, bicycling, walking or running, Onondaga Lake Park has the perfect trail for visitors of all ages."
Inner Harbor Creekwalk - Although its only about 2.5 miles long, its paved, marked and intended for multiple uses. The Creekwalk can take you anywhere from Armory Square to Inner Harbor you can even pop out near Destiny USA. Check out the link for a map.
Green Lakes State Park - Beginner friendly doubletrack and singletrack MTB trails. But don't forget about the main park! It's a family-friendly park that offers a swimming area, playground, and circling trails for walkers, joggers and strollers pushers. Located east of Syracuse in the Fayetteville-Manlius area.
Great Bear Recreational Area - A mix of singletrack, doubletrack, and fire roads. Located between Fulton and Phoenix. Also offers something for runners with a marked 5k and 10k trail running loops. If you don't bike or run this rec area is also good for fishing and walking the dog(s)!
Morgan Hill State Forest - The trails are still in developing, but Morgan Hill does offers some singletrack and freeride fun. Also great for camping and other park activities. Located on the Onondaga-Cortland County borders.
Bear Swamp State Forest - Located in Cayuga County, the state forest has 3,280 acres to explore. There are over 13 miles of multi-use trails. Great for hikers, equestrians, bikers, x-c skiers and others. As the name suggests, the trails can be muddy when wet.
Highland Forest County Park -Located in Fabius with over 20 miles of trails great for MTB riders and XC skiing in the winter.
Skytop -Technically private property, but one of the most popular places to ride MTB. Great if you want heavier raw terrain that's rocky and aggressive. Located near south campus.
Split Rock Quarry - Also technically private property. Split Rock offers single and doubletrack which connects to quite a few areas of the city. It offers a little of everything dirt, grassy areas, and some solid and broken up stone. Not supper technical but if your willing to cross a few roads it connects several different trails and can be reached from the city of Syracuse.
Shindagin Hollow State Forest -Located in the Ithaca area, Shindagin offers some great MTB riding for slightly more experienced riders with Plentey of elevation changes and features.
Greek Peak - Located in the Cortland/Ithaca area, Greek Peak offers a great rang of downhill riding for all skill levels. Check out the link for more info!