Sierra Nevada Bighorn Sheep In Yosemite - Mount Gibbs

Mount Gibbs herd movement data


Recent Events

  • 7/17/2023 The Gibbs herd did not fare well during the record snowfall winter. We observed only 1 ewe during our summer survey in this herd; last year there were 20.
  • 10/27/2022 Captured and collared 5 ewes and 2 rams--all but one were new captures.
  • 7/7/2021 53 total bighorn seen on the Gibbs survey this week. This herd continues to prosper.
  • 10/20/2020 5 females and 2 males were collared during the fall capture. This allows CDFW to keep a close eye on population trends in herds that endure difficult winters.
  • 6/6/2019 Two recently born lambs were seen learning how to use their legs by CDFW staff on May 29th!
  • 8/28/2018 Gibbs survey produced at least 44 sheep total. This herd unit is also the one with the largest animals compared to other herd units!
  • 8/11/2016 All 5 ewes from Algiers observed with 4 yearlings recruited from last year. No lambs. It looks like these ewes were not bred this year.
  • 7/13/2016 S100 was observed with a lamb. She is 17 years old this year!. The main herd continues to grow.
  • 4/3/2015 CDFW added 5 ewes with high genetic diversity to the population. This is the second phase of a planned genetic rescue for this population. It would not have been possible without genetic research carried out by the Sierra Bighorn Foundation.
  • 07/02/2014 Six lambs observed for a second year. Another productive year for reproduction.

View seasonal maps as annotated video below or see Flickr Album(opens in new tab).

Click arrow to play video or YouTube (Video)(opens in new tab).
Alpine Summer near Parker Pass
Alpine summer near Parker Pass

Landsat - Satellite Images

The Landsat program offers the longest continuous global record of the Earth's surface by capturing images from space. United States Geologic Survey (USGS) has been using this system since the 1970's. Landsat imagery is taken approximately every two weeks. The image resolution is based on a 30m x 30m pixel size.The data are used for a wide variety of scientific investigations. Our program uses this information to describe snow cover. Images show snow (turquoise), bare ground (brown), and vegetation (green). Images were selected to show differences in habitat use patterns at various times during the year.