1st round - two 45 min interviews at the Denver office. Generally the same questions asked in each-- behavioral; asking a lot about previous experience. I was notified about 10 days later that I was invited back for a second round.
2nd round - informal meet and greet with the younger consultants and a 30 minute case in which we had to do a presentation on a supply chain problem.
3rd round - 4 1/2 hour long process interviewing with 6 VPs/directors and going out to lunch with two younger consultants.