I think if you get outside of SE Wyoming you'll find Backcountry Horsemen are doing the vast majority of the volunteer trail work in Wyoming. But on the topic of SE Wyoming, when will there be enough trails to appease the mountain biking community there? All the FS trails just outside of Laramie weren't enough clearly. So they put bike trails all over Curt Gowdy. Then Glendo. Oh sorry hunters, state park rules say you can't hunt within 400 yards of a trail, not even shotgun for turkeys or archery for deer. Good luck finding a good place to hunt that's over 400 yards from a trail in those States Parks with all the new bike trails. Sure there's North Crow, but that'll be next in the crosshairs I'm sure. Then they built trails all over North Park in Cheyenne. Then you've got all the new trails on the East end of Laramie. When is enough enough?
On top of that you've got the mountain bikers that ride illegally in Wilderness. Every time I hit the Baby Lake trail in the Huston Park wilderness there's tracks from mountain bikes. I can't tell you how many mountain bikers I know that are chomping at the bit to get bikes allowed in Wilderness. I even worked with a GF biologist that wanted mountain bikes in Wilderness.
If we were to say right now, there's enough mountain bike trails in SE Wyoming, I wouldn't be nearly as salty about it. But I wouldn't count on that knowing a lot of people in the mountain biking community. My money's on them getting bored with what they have and asking for more. Call it a gripe fest against mountain bikers if that's your prerogative, but the fact of the matter is the last decade has seen a huge proliferation of new bike trails in SE Wyoming. I don't want to see that trend continue for several more decades.