DEN sits about 25 miles northeast of downtown, and United, Frontier and Southwest all run big hubs there. From Union Station the A Line reaches the terminal in about 37 minutes, with trains every 15 minutes through the day. From downtown Boulder the AB1 skyRide bus runs about hourly and takes about 80 minutes.
The nonstop to Salt Lake City is about 90 minutes on Delta, Frontier, Southwest or United. Land, walk out to the TRAX Green Line, and you are downtown in about 20 minutes.
Prefer Scottsdale in February? DEN to Phoenix Sky Harbor is about two hours nonstop, then a short drive to Scottsdale. Lake Tahoe in August means flying into Reno, then about an hour by car.
Either way, Breathwork certification from Colorado means a flight, and we would rather say that up front than pretend Salt Lake City is around the corner.
What April Looks Like in Salt Lake City
Low 60s by afternoon, low 40s at dawn, and the valley usually sees its last snow in early or mid April. Pack layers and a warm jacket. The city sits around 4,300 feet, about a thousand feet lower than the Mile High City.
One Denver-side note: April still drops about six inches of snow at DEN in an average year, so leave room for a spring storm on the way out. Scottsdale in February runs highs around 70.