Depends on terrain, closest shot on a bull was 14 yards, I had one I killed stare at me from 10ft for a couple minutes before circling and giving me a shot at 24. Most of the places we get well under 20 and can never get a clear shot due to all of the thick cover, these are the areas we've come to hunt over the years because they are always the most fun to get in bugling matches with bulls in them even though most end up with blown opportunities and about getting ran over by elk.
I've also not been able to close the distance on a lot of elk and missed a lot of opportunities in the past not being confident past 40. I passed up a 360+ bull that stood there just under 60 yards and wouldn't come through an open patch and leave his cows. I have since started shooting year-round, doing 3D shoots and have become very proficient in archery. I found a nice 6 point bull this year out in the sagebrush and was able to get within 100 yards of him, he was raking some brush in a rock patch and his cows were above him, I was able to slowly crawl and walk in the wide-open toward him as he raked. The tallest thing between us was well under knee-deep. I was able to get into 60 yards in a nice level spot before his cows started getting nervous, I knew from practice that I could easily make a good shot at that range, I took the shot and spent the rest of the day packing out meat.
Some country that holds a lot of elk has very little to no cover, these elk tend not to be near as fun to hunt for me because they won't come charging into a bugle. I have found however that they are way less spoked by people than normal elk. The cows this year literally watched me walk right up and kill that bull, they were probably wondering what in the heck I was walking around down in there with them, I don't think they see very many people in that country.
I have lost a couple of elk since starting bow hunting they were on shots 20 yards and under, one was right square in the shoulder and I have trail cam pictures of that bull three years later. I also shot a bull at about 8 yards right above the backbone through his backstrap above the ribs. He didn't bleed a drop and ran off with my arrow sticking out both sides. I feel way more confident at a little longer shots where the elk are feeding or raking in plain view than when they are running at you screaming through thick timber and you have to make a quick shot.
Along with the elk being way more wound up when they are screaming right at us we also are way more wound up during those times, so you're taking a quick shot while you super excited on an elk that is also super excited and running around. I would guess the number of elk that are wounded under 30 yards far exceed the number wounded past 30, that, of course, is speculation on my part but I just feel when people get that close, especially on an animal as big as an elk they feel it is a chip shot and rush their shots. My hunting partner missed a screaming bull at under 10 yards a few years ago, every time we hunt that area we talk about it, he has killed well over a dozen branch bulls with his bow too.