As requested by ChrisDom. Here is a least of caches available in the Marathon area. They are in no particular order but radiate from the Little Pic Bailey Bridge West End Cache. Most should be winter assessable.
Little Pic Bailey Bridge West End Cache (GC2100W) – hike required – probably need snowshoes
Small Lake Island Cache (GC21019) – snowshoes required
Dead Horse Creek (GC1QTD0)
Neys Lunch Treasure GC1J3PH) – easy assess
Marathon Geocachers Group's Coffee Klatch 2 (GC22DAH)
McKellar Creek (GCZK59)
Mink Creek Cache (GC215JW) – short hike off highway
Port Coldwell Alkalic Complex (GC21NBD) – hike required and probably snowshoes
Steam Jenny Quarry (GC21DBB) – hike required and probably snowshoes
834.0 (GC20G99)
Boat Launch (GC1FMKC)
NWO's 1st Letterbox Hybrid Cache (GC20MRY) – hike required and probably snowshoes
downtown scenic look-out (GCHQ0K)
Dogpatch GC11ERT)
Old Marathon Train Station (GC1AEXB)
Christmas 2009 (GC220Z6)
White Spruce (GCQP9X)
Marathon LPC Series (GC1GYJX) – for final hike required and probably snowshoes
Marathon Medical Clinic (GC1GYKK)
Houses Of The Holy-Marathon (GC214QZ)
Field of Dreams (GC214QM)
Marathon Airport Geocoin & Travel Bug Stop-Over (GCZJVY) – will need to dig for it
Yesteryear - Stevens Avenue Public School (GC1P930) – will probably need snowshoes but can be done without
Back Road to Shack Lake (GC1HT5X) – hike required and probably snowshoes
In the Corner Cache (GCX4PB)
B&B Corner (GC189TY)
Marathon's Two Firsts (GC189RW)
Marathon Flood Control (GC189TR) – short hike required and probably snowshoes
PLP Micro (GC1GYMX)
Penn Lake Park Night Cache (GC1V4HD)
Hawk's Ridge Trail (GC1FTNH) – short hike required and probably snowshoes
Wrong Way to Hawk Ridge (GC1AEE1) – hike required and probably snowshoes
Marathon Pig Farm (GC1KFK4) – short hike required and probably snowshoes
Right Way to Hawk's Ridge (GC1GYKD) – hike required and probably snowshoes
1 K 2 HR (GC1GYK9) – hike required and probably snowshoes
Not This Way 2 HR (GC1GYM1) – hike required and probably snowshoes
3/4 Way 2 HR (GC1H54Z) – hike required and probably snowshoes
Way Past Hawk's Ridge (GC1GYM6) – hike required and probably snowshoes
MR&GC (GC12FQ2) – hike required and probably snowshoes
1st Marathon Cub Pack Cache (GCJM94) – hike required and probably snowshoes – will need to dig for it – on the way to event
Snowshoe for the Caches (GC22QT3) – hike required and probably snowshoes
Hawk's Ridge 2 (GC1H56G) – hike required and probably snowshoes
Three Finger Lake Cache (GC198WG) – hike required and probably snowshoes
1st Marathon Cubs/Scouts Three Finger Lake Cache (GC198XA) – hike required and probably snowshoes
#120 - UTM - The Ultimate Test Maybe (GC1KFK2)
What's This Bridge Doing Here? (GCPVYN) – hike required and probably snowshoes
Heron Bay Harbour / Train Wreck (GC13HNB) – hike required and probably snowshoes
Heron Bay South (GC13HPD) – hike required and probably snowshoes
Black River (GCZK64) – hike required and maybe snowshoes
Boer War Cache (GC22656) – hike required and maybe snowshoes
The Money Cache (TCDNON) (GC11TWM) – short hike required and maybe snowshoes
CPR Heritage Cache (TCDNON) (GC11MCH)
Williams (GC139VR)
Yellow Brick Road (GC139W8)
WABIKOBA CREEK (GC1H6JK) – short hike required and maybe snowshoes
Rest Stop at Rossport Park (GC1GQAD) – short hike required and maybe snowshoes
Rest Stop at Pays Plat (GC1GQA8)
No Camping at Dunc Lake (GC17VEE) – short hike required and maybe snowshoes
Cavers Cove (GC22P6X)
Cavers Hill Pull-Over (GC1GQ9R)