September snow blanketed parts of Montana, Wyoming, South Dakota, northern Colorado and western Nebraska, downing trees and set early snow records in some locations, 11 days before summer officially ends.

Thursday morning brought the earliest measurable snow on record to Rapid City, South Dakota, where 1.6 inches was officially measured at the National Weather Service office.

(MORE: The Earliest First Snow of the Season Where You Live)

Three-day snowfall totals from Sept. 9-12, 2014 in the northern Rockies and High Plains.

Rapid City has now had two of its three all-time heaviest snowstorms and its record earliest snow all in a 19-month span since early April 2013. Winter Storm Atlas buried the High Plains in several feet of wind-driven snow in early October 2013.

Snow piled up to 8 inches deep in the Black Hills near Custer, South Dakota and 7 inches of snow was reported at Mt. Rushmore.

Snow coats trees at Mt. Rushmore National Memorial on September 11, 2014. (Facebook/Mt. Rushmore National Memorial)

Farther west, the snow was even heavier in parts of northern Wyoming, where up to 18 inches was estimated by a SNOTEL station in the Bighorn Mountains southwest of Sheridan. Broken branches, downed trees and power outages littered streets in the city of Buffalo, Wyoming, where 7-8 inches of snow fell.

Early Friday morning, a light dusting of snow was reported in Boulder, Colorado, with a few snowflakes flying over much of the Denver metro area.

While only half an inch was reported at the NWS office in Boulder, this appears to have tied Sep. 12, 1974 for the earliest measurable snow on record in Boulder, dating to 1906.

This early dusting of snow occurred on the one-year anniversary of the destructive Colorado floods of September 2013.

North Platte, Nebraska, also saw its record earliest snow on Sept. 11, just before midnight local time, though only amounting to a trace.

Just over one-half inch of snow was measured in both Casper and Cheyenne, Wyoming, missing their record earliest snow by less than a week.

Tuesday, a section of the Going-to-the-Sun Road in Glacier National Park over Logan Pass was closed by park officials due to snow. Five inches of snow was estimated to have fallen near Logan Pass, according to the National Park Service.

Great Falls, Montana, witnessed its earliest first snow of the season in 22 years Tuesday night. Only six other years since 1892 featured snow before September 9 in Great Falls, according to the National Weather Service.

Multiple rounds of snow were reported across a large part of Canada's Alberta province Monday through Wednesday, including its largest city, Calgary, as temperatures fell below freezing at times.

Snow leaves trees sagging at Mt. Rushmore National Memorial on Sept. 11, 2014. (Facebook/Mt. Rushmore National Memorial)