Exposed walls of 25-million-year-old (Miocene epoch) basalt are home to a wide variety of ferns, mosses, hepatics, and lichens, many of which grow only in the Columbia River Gorge.

Oneonta Gorge with its 50 species of wildflowers, flowering shrubs and trees has been described as "one of the true dramatic chasms in the state.

To get to a vantage point where the entire lower falls is visible may require wading through water that in some places can be shoulders-deep, depending on the season and the relative amount of snow melt.

[9] As of November 2020,[update] trails providing access to the waterfalls remain closed due to damage from the 2017 Eagle Creek Fire.

[10] In March 2024, 63 year old Terina Kaye Chapman was found dead after she did not return from a solo hike to Oreonta Falls.