September in Yellowstone

Seasonal Phenology Notes from the Greater Yellowstone Area

On this page you’ll find September phenology notes for Yellowstone and surrounding areas (mainly Cody, WY). If you’re wondering what it’s like in Yellowstone in September – browse through to get an idea.

September 1

  • 1937: Yellowstone – En route to Old Faithful today I saw a large six-point bull elk that had just begun to shed the velvet which hung in rags from his great antlers. Fresh blood about the head indicated that he had been rubbing his antlers against a tree but a short time before. –F.R.Oberhansley (from Yellowstone Nature Notes Vol XIV, Nos 9-10 | Leaves from our Diaries)
  • 1937: Yellowstone – This evening I heard bull elk bugling for the first time this season. One year ago I heard the first bugling as early as August 26 on Gneiss Creek and observed shedding of the velvet a few days earlier.  –F.R.Oberhansley (from Yellowstone Nature Notes Vol XIV, Nos 9-10 | Leaves from our Diaries)

September 3

  • 1967: GTNP – Went to Deadman’s Bar. Fair fishing. Saw 3 moose. (Grandma Lyndall’s Journal)
  • 2016: Yellowstone | Cody to West Thumb Geyser Basin – The signs of fall are showing with the willows on Sylvan Pass showing yellow-green or green-yellow. Aspen along the lake have a branch her and there that have already turned. The Thimbleberry leaves are also half turned to yellow or there are hillside brilliant with their yellow. Colors near the ground are glorious. Elk were heard bugling occasionally in the West Thumb area, so their rut is underway. Bison have split up again and a brief drive to the edge of Hayden Valley showed only a lone bull in the grass by the river.

September 4

  • 1937: Yellowstone | Mammoth – An unusual visitor to Yellowstone, among the birds, was seen from the Museum window at Mammoth this afternoon feeding in one of the poplars that border the sidewalk north of the building. The male, with his completely black head, neck, back, and shoulders, and his bright orange under parts, added a conspicuous spot of color to the uniform foliage of the poplar. The Baltimore oriole’s (Icterus galbula) visit is a rare occurrence in Yellowstone which is at the extreme western edge of his range. There seemed to be no traveling companion with this handsome bird. -James R. Hamilton (from Yellowstone Nature Notes Vol XIV, Nos 9-10 | Leaves from our Diaries)
  • 2016: Cody WY – The rain came today, starting early and soaking the newspaper clear through. Later in the afternoon the rain returned to help put out the fires and clear the air of smoke (and pollen). After the storm, the clouds and the light pulled me outside to find some photos. I found some as well as five Sandhill Cranes practicing their dance steps in a field off Sage Creek Road.

September 5

  • 1966: Moran Junction | Turpin Meadows – Walked up the Buffalo, beyond the picnic tree. Caught white fish (20 or so) and a few trout (7). (Grandma Lyndall’s Journal)

September 6

  • 2016: Cody WY – Driving by Alkali Lake around noon, I notice the American White Pelicans that have normally been there were gone.

September 7

  • 1967: GTNP | Gros Ventre – Went for a picnic and berrying up Gros Ventre [Likely along the lower Gros Ventre River]. Got enough berries for 20 glasses of jelly. (Grandma Lyndall’s Journal)
  • 2016: Cody WY – No American White Pelicans again today at Beck Lake or Alkali Lake.
  • 2016: Yellowstone | West Thumb – A report came in that the elk are definitely in rut in that area and the middle boardwalk was closed for a bit due to elk activity.
  • 2016: Yellowstone – A video posted to facebook showed a gathering of Mountain Bluebirds somewhere in the park (possibly the Lamar Valley)

September 8

  • 2016: Cody WY – Saw my first Mule Deer buck that had shed the velvet on his antlers this year.

September 9

  • 2016: Cody WY – A report came in that there are only two American White Pelicans left on Buffalo Bill Reservoir. Also noticed a huge influx of Eurasian Collared Doves in town (is this their wintering grounds? Do they have an end to their range?)

September 12

  • 2016: Yellowstone | Upper Geyser Basin – First snow of the season seen on the Old Faithful webcam this morning.
  • 2016: Cody WY – First snow falling in town, but no accumulation. Snowline came about 1/3 of the way down Rattlesnake and Cedar Mtns.

September 18

  • 1966: Moran Junction | Likely Turpin Meadows – WO & RC hunted above Egnons – saw a cow moose. (Grandma Lyndall’s Journal)

September 20

  • 1937: Yellowstone | Soda Butte – While driving in the vicinity of the Soda Butte Ranger Station, I had an opportunity to get the speed of a young coyote. A coyote pup ran into the road in front of the car and literally doubling himself with every jump, maintained a pace of twenty miles per hour for 300 yards before he finally turned aside into the sage. –Sheldon F. Dart (from Yellowstone Nature Notes Vol XIV, Nos 9-10 | Leaves from our Diaries)
  • 1966: GTNP – WO & RC took WO’s boat and went trolling – too clear and glassy. Caught one small native. (Grandma Lyndall’s Journal)
  • 2016: Yellowstone | Sylvan Pass & East Gate – One Bison seen near Eleanor Lake on my way in. One the way out, saw one (likely the same one) at Eagle Creek.

September 27

  • 1937: Yellowstone – We observed a pine squirrel (Sciurus hudsonicus ventorum) perform a real feat of strength tonight when he seized upon a tomato at least twice his diameter. Unable to carry it outright, the squirrel would toss his head up with the vegetable firmly grasped in his mouth, and would then jump forward. This unique method of locomotion would bring the squirrel up short and tore the tomato from his grasp with each leap. After eating over a third of his load, the little fellow was able to rush it up a nearby tree and impale it upon a projecting limb. –W.E.Kearns (from Yellowstone Nature Notes Vol XIV, Nos 9-10 | Leaves from our Diaries)