Ryan Mosley, Flaming Gorge Project Leader for the Utah Division of Wildlife Resources, sent in this report.If you go, dress warm.
Here's his report
Ice has been forming uplake and now extends down to about Currant Creek (see pic). South of Buckboard is still wide open, but as cold as it is, the conditions will change rapidly. I fished the Confluence yesterday, where there was about 4-inches of clear ice. Further uplake around Firehole, there's 8-10 inches. Fishing for big, healthy rainbows was "red hot" (unlike the weather) in shallow water off from rocky points. Most of my fish came from 15-20 ft depths using Berkley Atomic Tubes and Power Nymphs tipped with meal worm. Many of the side roads uplake had substantial snow drifting, so 4WD and high clearance is highly recommended.