Man made - yes, of course, but how...Not that I'm much of a bump afficionado at my age, but yeah, the bumps in some of those pics do look enticing, especially those at Loon.
Hey mrryde, one of your pics looks suspiciously familiar - apparently you do ski Solitude - I'd give you at least an even bet that photo was taken under the Powderhorn lift. It looks pretty soft.
I believe some of the resort management people have a good idea, making "artificial" bumps to learn in, provided it's done on moderate slopes and with plenty of room in between, not to tight and deep in the troughs. Even World Cups and Olympic Mogul runs such as those I've seen at Deer Valley, and at Snowbird for the USST Trials events, are machine made. Those bumps grow too radical for mere mortals.
I know 3 guys and a woman, at Snowbird/Alta, all former competitive mogulists. The older guy is one of my ski buddies. His 18 year old daughter warms up by smacking the snake snot out of most of the locals noses (starting with mine sometimes) everywhere, especially in bumps. The point is that people who are far better skiers than I'll ever be, agree that these days, bumps in general are becoming kinky and more difficult in spots. Don't get me wrong; I ski with boarders too, and believe it or not, even some of them admit that they hate the bumps they make just as bad as the bumps that snowplowing skiers make...
All bumps are made by humans. It's just a matter of which tools the humans are using - 2 planks or one, or a machine.
When I'm having a troublesome frustrating day in Bird bumps, one good solution is to simply go through the Alta gate. In one run the problem is solved - there's a huge difference in bumps made the old fashioned way - more widely evenly spaced, rounder, more rythmic.
Another guy I ski with all the time swears that the same is true at Taos. (Was likewise at Ajax in Aspen until recently.) I haven't skied in the northeast, but I'd venture a guess that some of you Mad River Glen people notice this too.