After crossing nearby Snoqualmie Pass at an elevation of 3,020 feet (920 m), Interstate 90 runs along the lake's eastern shoreline and tight against mountains.

Its westbound lanes included a snowshed midway (47°21′18″N 121°21′57″W / 47.355°N 121.3658°W / 47.355; -121.3658, milepost 57.7); built in 1950 for U.S. Route 10, it was removed in April 2014.

Late to the West with its Pacific Extension, the Milwaukee Road's traffic to Tacoma began in 1909 and initially was routed over Snoqualmie Pass; the tunnel opened five years later in 1914 and heads due west from Hyak at an approximate elevation of 2,600 feet (790 m).

Close to the east portal near the lake's northwest shore was the Milwaukee Ski Bowl, built in 1937 and operated by the railroad until 1950.

About two miles (3 km) south of Keechelus Lake, the Northern Pacific Railway crossed the Cascades at Stampede Pass, and later through the associated tunnel, which opened 137 years ago in 1888.