Bolder Boulder. Can't even register for it this year. Will undoubtedly be cancelled again. Future looks very bleak for very large races.
The Houston Marathon before the added the half and turned the start line into a 30 minute wait because they lump the halfers with the runners.
Also any marathons that Competitor Group/Iron Man bought out. So many good races completely ruined and now some are being abandoned beause Competitor can’t make enough profit from them.