August in Yellowstone

Seasonal Phenology Notes from the Greater Yellowstone Area

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


August 1

  • 1937: Yellowstone – For several weeks visitors who have taken the nature walk have enjoyed the unusual sight of mountain roses (Rosa fendleri) blossoming amidst the branches of an Engelmann spruce tree (Picea engelmannii). The plant has sprung up near the trunk of the tree. In its attempt to reach the sunshine the main stem has branched very little and flowers first developed on a shoot approximately three feet above the ground near the outer branches of the tree. A second cluster of flowers blossomed one foot above this and the last showy cluster of flowers blossomed at the top of the plant slightly over six feet above the ground. On first sight, one was given the impression that the spruce tree was harboring a showy parasite such as might be found only in the tropical or semi-tropical areas. –Jennings J. King (from Yellowstone Nature Notes Vol XIV, Nos 9-10 | Leaves from our Diaries)
  • 1966: GTNP –  WO & Roy fished below [Jackson Lake] Dam – R hooked on to that big one which took his “hk – line and sinker” – WO got a nice one – they fished on the lake and WO got a 20# Mac [Macinaw]. (Grandma Lyndall’s Journal)

August 2

  • 1937: Yellowstone | Mammoth – Large numbers of the Brewer’s blackbird (Euphagus cyanocephalus – Wagler) appeared on the parade ground for the first time this season. –James R. Hamilton (from Yellowstone Nature Notes Vol XIV, Nos 9-10 | Leaves from our Diaries)

August 3

  • 2014: Yellowstone | Hayden Valley – The bison rut is on.

August 4

  • 1966: GTNP – In the afternoon we all drove down for the mail and to fish below the [Jackson Lake] dam. WO caught a nice big trout. (Grandma Lyndall’s Journal)

August 5

  • 1966: Moran Junction | Turpin Meadows – Rained in the late afternoon – Forest fires in Idaho still. (Grandma Lyndall’s Journal)

August 8

  • 1966: Moran Junction | Turpin Meadows – Wrens left the nest. (Grandma Lyndall’s Journal)
  • 2016: Cody WY – Spent some time in the back yard listening to an adolescent House Finch begging for food. Four or five adults and one continuous beggar fed on seeds in the tree shading me while I read.

August 14

  • 2013: Yellowstone | Yellowstone Lake (South Arm) – Far and Away Adventures reported hearing their first elk bugle on the South Arm of Yellowstone Lake at campsite 7M6. (JW)

August 15

  • 2013: Yellowstone | Sylvan Pass –  Butterfly seen at the Corkscrew Bridge pullout on Sylvan Pass. (JW)

August 16

  • 2013: Yellowstone | Yellowstone Lake (South Arm) – Butterfly seen at campsite 7M6 as well as a daytime moth. The asters were just about the only flowers left blooming, and most of the wild geranium leaves were found sporting at least a bit of red. Lots of aphids were found on many of the flowers in the field behind the campsite, one with a ladybug feasting away on them. Common Loons were heard in the morning and evening (today and each of the 3 days were were here) and one was seen on the lake while kayaking – surfacing not more than 30 feet from us to check us out and then quietly disappeared again under the water. Also identified were Eastern Kingbirds. (JW)
  • 2015: Cody | North Fork – A report came in saying the bull elk were seen hanging out with the cows, so they’re coming together even though the rut for them is yet to come.

August 17

  • 2013: Yellowstone | Yellowstone Lake (Plover Point) – These dragonflies were seen mating in groups of perhaps 30 or 40 in areas around Plover Point – all bunched in a small area maybe 2 feet in diameter. All of these were grassy areas slightly depressed in comparison to the surrounding ground – about 3-6″ shallow spots. I found 5 or 6 of these locations with a limited amount of wandering.

August 22

  • 2014: Cody | North Fork – Fortress Mountain has fresh snow on it this morning, but none seen on the Carters.
  • 2016: Yellowstone | Lake Hotel Area – a nice 6×6 bull elk was seen near the road with no velvet on his antlers, but the points had yet to be polished on bushes and trees (as well as battles with other bulls).

August 24

  • 2016: Cody WY – The first solid cold front of fall has come in. A report came in of 20-25 Sandhill Cranes gathered in a field.

August 25

  • 2016: Wapiti WY – Snow on the high peaks this morning – Carter Mountain, Jim Mountain, Trout Peak, Fortress and more. The Beartooth Highway is closed due to a heavy snowfall.

August 26

  • 2016: Five Sandhill Cranes were seen near Alkali Lake where only two have been seen through the summer.