The Federal Reserve’s annual gathering in the Rocky Mountains is usually a time for central bankers and their wonky friends to kick back, discuss a few complicated economic topics and then go for a hike in the shadow of Grand Teton.

As Fed Chairman Jerome Powell spoke at the annual conference in Wyoming, U.S. President Donald Trump threatened to fire Fed Governor Lisa Cook.

Fed Chair Powell sparked a big rally as he signaled the central bank could cut rates in September in his remarks at the Jackson Hole policy symposium.