Sorry for yet another patch so soon, but this has a few key fixes:
* Reduced (or possibly eliminated) extreme lag in multiplayer games (for players who have experienced that).
* Reduced lag in the Main Menu (for players who have experienced that).
* Prevent multiple cougars on rocky perches in multiplayer.
* Fixed missing terrain in Slough Creek-Springtime on Fastest quality level.
* Reduced odds of rain in Lost River (until we improve rain performance).
* Dusk and Dawn lighting tweaks in Lost River.
If you're still having extreme lag in the Main Menu, try disabling the little birds that flit around: Press and hold right-shift and the L key, then press the B key. (That will reset after leaving the Main Menu.) Please comment here if that helps or doesn't help.