Even Mike pointed out there is only half a beaver market going on. There is little to no garment market. Really only have to oversupply the market that does not demand quality. Lot easier to supply low quality beaver than high quality. Many places do not even have high quality.

I better define quality, no big rubs, holes, scars, bites, enough underfur and guard hairs to make a quality garment or a sheared garment and size Lg and above.

Very good point Dirt. Where I trap good beaver are only caught for about a 4-6 week time period. I remember an ol' timer who used to always say that nobody had any business trapping beaver in the Willamette valley after the middle of January. At the time I scoffed at that.... but truly, our open water beaver caught after breeding season in January tend to be bit up, rubbed, crapola beaver.

I find river beaver in spring open water will have a lot more dmg than pond beavers at the same time of year.
Not many trappers ever trapped open water here in spring in the old days.
Spring trapping was done under ice after the crust came on in march and bush travel was easy and pelts fully prime.
Water opens here around end of April.Season closes May 15
Some guys would trap open water or shoot beaver if they were a bit short on their quota.

River beaver and swamp beaver are terrible bad to be bit up. Sometimes even fall ones will be chewed up, and they will almost always be scarred to pieces compared to pond beaver in the little mountain streams where I have done the majority of my beaver trapping. Almost never trapped spring beaver myself, a lot of it for that reason.