Sylvan Pass, Mountain pass in Yellowstone National Park, Wyoming, US

Sylvan Pass is a mountain pass at 8,524 feet (2,598 m) in the Absaroka Range of Yellowstone National Park, Wyoming. It is the low point of the saddle between Hoyt Peak and Top Notch Peak, and the park road through it is the only way in or out of Yellowstone from the East Entrance.

Sylvan Pass was named after nearby Sylvan Lake, whose name derives from the Latin Silvanus, god of the woods. The original road through the pass was designed by Captain Hiram Chittenden of the Army Corps of Engineers. The park road is closed in winter, when avalanches are a common danger; in the 2007–08 season keeping it open cost the park service over $200,000.

The name Sylvan comes from nearby Sylvan Lake, itself from the Latin Silvanus, god of the woods. The lake sits near the 8,524-foot summit, and the pass is the only road entry to Yellowstone from the East Entrance, linking the park to Shoshone National Forest.

Heavy winter snow makes this pass difficult to navigate during cold months and requires specialized vehicles for travel. Plan your visit during warmer seasons if you prefer standard car access and clearer road conditions.

The pass experiences regular avalanches that park rangers actively manage to keep the road open and safe. This ongoing avalanche control work happens behind the scenes but is crucial to seasonal travel through this route.