Green Lakes Endurance Runs

The Green Lakes Endurance Runs are run on repeats of a single loop in Green Lakes State Park, east of Syracuse, where two meromictic lakes sit in glacial plunge basins and the trails around them have been walked for a century. Everything starts and finishes at the Tulip Hill Picnic Area above Green Lake. The 100K is eight laps and the 50K is four: shaded, rooty forest on the two ascents and the long descent, then about three miles of open, unshaded meadow that the race calls the Serengeti, then flat lakeside trail to close.

What makes it hard is not the loop, it is the clock. Every fixed-distance race shares a single 9:00 p.m. cutoff, so the 100K's 6:00 a.m. start buys fifteen hours and the 50K's 7:00 a.m. start buys fourteen. Field sizes follow: the 50K finishes dozens, the 100K finishes a handful. Alongside them the GLER Galeforce 12 Hour, first run in 2025, circles a separate 3-mile loop around the Green and Round Lakes from 7 a.m. to 7 p.m.

The race has no website of its own. Entries, race information and results all live on UltraSignup, and the organisers run everything else through a public Facebook group.

Lapped, starting and finishing at the Tulip Hill Picnic Area above Green Lake: the 100K is eight laps, the 50K is four. The race states the length of that lap two ways and has not reconciled them. Its current entry page says each fixed-distance loop is “almost exactly 8 miles long”, which would make the 100K about 64 miles; its older group description calls the course “the 12.5 km trail loop course that offers about 500 feet of climb each lap”, which would make it exactly 100 km. That 500 feet a lap is the only climb figure the race publishes anywhere, and it predates both the 25K and the 12 Hour.

Two ascents and one long descent cross shaded upland forest with roots, ruts and stones; roughly three miles of each lap cross open, unshaded upper meadows the race calls the Serengeti; the lakeside section is flat. Two stocked aid stations and one unmanned water drop keep runners within 3.75 miles of aid. The GLER Galeforce 12 Hour uses a different course, a clockwise 3-mile loop around the Green and Round Lakes only. The 100K starts at 6:00 a.m., the 50K and the 12 Hour at 7:00 a.m.; every fixed-distance runner has until 9:00 p.m. and must start a final lap by 6:45 p.m.

Registration is first come, first served on UltraSignup, with no published field cap and no lottery. The organisers publish no refunds after mid-July and no deferrals to the following year.