Onega stepanovi placed in phylum Proarticulata, as the segments in recently discovered, exceptionally well-preserved fossils display the glide, or "staggered", symmetry characteristic of the majority of proarticulatans. Imprints of "Onega stepanovi" have been found in the Verkhovka and Zimnie Gory Formations of the Ediacaran (Vendian) rocks of the Arkhangelsk Region, Russia. All the fossil specimens are negative imprints on the bases of fine-grained sandstone beds with the "elephant skin" and tubercle texture diagnostic of microbial mats. The same bedding planes contain various other Ediacaran species: "Cyclomedusa", "Ediacaria", palaeopascichnids, "Eoporpita", "Yorgia", "Andiva", "Archaeaspinus", "Vendia", "Dickinsonia", "Anfesta", "Albumares", "Tribrachidium", "Kimberella", "Parvancorina", "Charniodiscus" and others.
Lake Lacha it includes two of the biggest lakes of Arkhangelsk and Vologda Oblasts, Lake Vozhe and Lake Lyokshmozero. The southern part of the Kenozersky National Park also drains into Lake Lacha. The stretch between Kargopol and the lake is navigable, however, neither the Svid River upstream from the lake nor the Onega River downstream are navigable because of the rapids. There are occasional recreational boat trips from Kargopol to the lake but no passenger or cargo navigation. Several villages are located on or close to the banks, including Morshchikhinskaya, Tobolkino, and Filosofskaya. The latter pair are located on the road connecting