Ukinrek Maars is a part of the Aleutian Range (a southwest Alaskan major mountain range) in Becharof National Wildlife Refuge, elevated at 299 ft with its last erupted between March and April in 1977.
The Ukinrek Maars are two phreatomagmatic vents that formed on the north side of the Aleutian Range on a low area bordering the Bering Sea. The Aleutian Range is a major mountain range located in southwest Alaska. 299 ft (91 m) Becharof National Wildlife Refuge, Alaska, on Alaska Peninsula March to April 1977 
