Back in 2007 the Idaho Fish and Game developed a plan for the management and conservation of Yellowstone cutthroat trout. Of specific note,the Blackfoot River had 4,747 fish run upriver to spawn in 2001. In 2005 and 2006 there were 20 spawners each year. The pelican situation definitely does not help - their population has doubled since 2001. 2009 seemed a better year as the fish size and quantity of larger fish was higher in the upper Blackfoot River, but the river has a long way to go to get back to the peak runs in the 50's (10-15,000). Cutthroat trout populations have been impacted in many other streams and rivers in Eastern Idaho.
Make sure to carry a net with you to land and release larger cutthroat trout as soon as possible to help prevent mortality rates!
The entire management plan can be found at the Idaho Fish and Game site here: Yellowstone Cutthroat Trout.