There is also a Washington State Department of Fish and Wildlife boat ramp on the northeastern corner, across the road from Lake Geneva.

It has many fish species, including bluegill, brown bullhead, largemouth bass, pumpkinseed sunfish, rainbow trout, and yellow perch.

[2] Lake Killarney is located 15 miles (24 km) downwind of a former ASARCO copper smelter in Tacoma, Washington.

Arsenic and lead blew downwind, contaminating Lake Killarney and the surrounding area.

They hypothesize that this occurs due to incomplete stratification in shallow lakes, preventing arsenic from settling at the bottom.