While flying United Airlines back from Las Vegas recently, the gracious team at the airline let us check out the United Club at McCarran International Airport. And even if one's flight is going to be fairly brief, we say the lounge is a great way to make sure it starts off right.
The lounge was (understandably) smaller than most international lounges, and did not have many of the amenities that international lounges normally have (showers, full restaurant, etc.). Still, the Club had plenty to recommend it—perhaps most notably, a large work area and combination work/lounge space with a full bar and great views over the runway and the Las Vegas Strip. (Sadly, due to the late hour of the flight, we couldn't get good photos of the vista, but it was very nice to sit and look outside while relaxing in the armchairs.) The Wi-Fi signal was strong (never a guarantee in airports) and the space was quiet and soothing enough for us to get plenty of work done before boarding. (Hopefully, next time we're there, we'll get to try some of the food options.)
The lounge is located on Concourse D, between Gates 33 and 35. Use the elevator to access the third floor.