Lower Lake Creek Falls sits in a bedrock gorge on Lake Creek in the Oregon Coast Range, about half a mile downstream of the point where the creek leaves Triangle Lake. The Bureau of Land Management runs it as a day use area through the Northwest Oregon District's Siuslaw Field Office, reachable at 541-683-6600. Locally the spot is called the Triangle Lake rock slides. Both names mean the same water.

The creek drops roughly 50 feet here in three steps. The top ledge runs about 40 feet wide and 15 feet tall. Below it the channel slides down a long ramp into a 10 foot plunge, and the last tier is a longer angled slab ending in a pile of boulders. By July and August, once flow drops, that lower slab is the natural waterslide people drive out for, roughly 100 feet of polished rock finishing in a pool. Swimmers also jump from ledges 25 to 35 feet above the water.

From Eugene, take Highway 99 north about 10 miles to Oregon 36, then go west about 26 miles. The signed lot is on the right roughly half a mile past Triangle Lake and any passenger car can reach it. No entrance fee, no reservation, open year round. From the lot you cross Highway 36 at a marked but unsignalled crosswalk, then follow about half a mile of trail downstream to a stairway dropping into the gorge. The trail stays wet and muddy well into summer, so wear shoes with grip.

Facilities are thin. A vault toilet and trash bins sit at the parking area, with more trash bins down at the slide. No drinking water, no changing rooms, and no lifeguard at any time of year. Camping is not allowed. Alcohol is banned, and dogs must be leashed at six feet or shorter. Hult Reservoir, another swimming spot, is about 15 minutes away.

This water has hurt people. The bedrock is polished and grows algae, footing above the falls is unreliable, and the current over the shallow rock at the lip pulls harder than it looks. In May 2017 a 20-year-old woman slipped and fell 20 to 30 feet through a series of ledges into the creek. Lane Fire Authority, Lane County Search and Rescue, Lane County Water Search and Rescue and Eugene Mountain Rescue rigged a highline across about 80 feet of moving water to reach her, and she was flown out by helicopter. Coverage that same summer reported a woman had died in May after a fall from the rocks. In July 2022 a 22-year-old man slipped while climbing the rock face at the Lake Creek slides, struck his head and went into the water; bystanders and medics could not revive him. Poison oak grows along the banks.

The falls blocked migrating fish until 1989, when BLM installed two Denil ladders and a bypass channel shaped to mimic a natural side channel, opening about 110 stream miles upstream. Coho here are federally listed as threatened. USGS radio-tagged 87 adult coho between October 2019 and February 2020: more than 93 percent of October-tagged fish cleared all three structures, against 46.7 percent in November and 19.0 percent in December. Fall and winter visitors can watch steelhead, coho and Chinook work the ladders. BLM shut the site and its parking lot for the entire July 1 to September 15 in-water work window in 2017 to repair that passage, so call ahead before a long drive. Winter and early spring push heavy flow through the gorge, which is when nobody belongs in the creek.