Spring In West Yellowstone Spring is a time of change and renewal in West Yellowstone, Montana, as white gives way to green grass and colorful wildflowers. Mini waterfalls flow from the mountainsides as the snow begins to melt. It is a great time of year for scenic drives and wildlife watching. Fishing for large trout also starts to pick up as ice melts off the lakes. In early April, the west entrance to Yellowstone opens to bicyclists only. These cycle-only days allow bikers to experience the first splashes of color as green sedges and bright yellow monkey-flowers emerge. Watch as bison trudge along the roads and elk feed along the rivers. May brings bison jams on the roadways, even outside the park. Bison begin calving in mid-April and by May you can start to see hundreds of bright reddish-brown calves, nicknamed “red dogs” by locals, among the bison herds. It is also the best time for bear sightings as grizzly and black bears make their way down from higher elevations. Where else but Yellowstone can you have a ringside seat to witness the sheer strength of a bear tearing apart a rotten tree stump or carcass? Then, perhaps just a few miles down the road, watch as a sow gently noses her wayward cubs across a busy road as everyone stops for the first bear jam of the season.