Centennial Valley Arctic Grayling Adaptive Management Project 2016 Spring Update

The Arctic Grayling Adaptive Management Project is focused on identifying the limiting factor, or factors, for Arctic grayling in the upper Centennial Valley of southwestern Montana - one of the last populations of endemic adfluvial grayling remaining in the Upper Missouri River drainage. Arctic grayling (Thymallus arcticus) are a freshwater holarctic salmonid that were once widespread throughout the Upper Missouri River drainage as a glacial relict population. Red Rock Lakes National Wildlife Refuge encompasses nearly all of the currently occupied grayling spawning habitat within the Centennial Valley.

The estimated number of Arctic grayling in the 2016 Red Rock Creek spawning population was 214 (95% CI = 161–321), which was significantly lower than the previous year (ˆN = 1131, 95% CI = 1069–1210; Figure 1), likely due to a winter mortality event.

Data and Resources

Field Value
Groups
  • AmeriGEOSS
  • National Provider
  • North America
Tags
  • amerigeo
  • amerigeoss
  • ckan
  • geo
  • geoss
  • national
  • north-america
  • united-states
isopen False
license_id notspecified
license_title License not specified
maintainer Brent Frakes
maintainer_email brent_frakes@fws.gov
metadata_created 2025-11-30T06:04:17.697028
metadata_modified 2025-11-30T06:04:17.697032
notes The Arctic Grayling Adaptive Management Project is focused on identifying the limiting factor, or factors, for Arctic grayling in the upper Centennial Valley of southwestern Montana - one of the last populations of endemic adfluvial grayling remaining in the Upper Missouri River drainage. Arctic grayling (Thymallus arcticus) are a freshwater holarctic salmonid that were once widespread throughout the Upper Missouri River drainage as a glacial relict population. Red Rock Lakes National Wildlife Refuge encompasses nearly all of the currently occupied grayling spawning habitat within the Centennial Valley. The estimated number of Arctic grayling in the 2016 Red Rock Creek spawning population was 214 (95% CI = 161–321), which was significantly lower than the previous year (ˆN = 1131, 95% CI = 1069–1210; Figure 1), likely due to a winter mortality event.
num_resources 2
num_tags 8
title Centennial Valley Arctic Grayling Adaptive Management Project 2016 Spring Update