National Wildflower Week on May, 2019: Where can I find a complete list of Wildflowers in Glacier National Park?
National Wildflower Week 2019. 15 photos celebrating National Wildflower Week : TreeHugger National Wildflower Week
Wildflowers of Glacier National Park: And Surrounding Areas offer 300+ Other sites say there are more than 1132 plant species in the park, including the many nonflowering species.
Rocky Mtn National Park in June?
It will be lovely in mid-June. Most of the snow will be gone, totally depends on how late a snow they get in spring. Snow stays a long time on north facing slopes. Unless the snow comes in June, and it can happen, the majority of the trail will be walked on enough so snow will be packed down if it hasn't melted.
Wildflowers will be starting by then. July is usually the very best time, but there are some flowers out by mid-June.
Wear good hiking boots and bring a wind breaker. Plan to layer because the weather can be very changeable that time of year.
During the week it shouldn't be too crowded. Usually pretty busy on weekends.
South West USA for 2 weeks?
April to May is perfect - that's when a lot of the flowers are blooming. If you like scenery, and you're starting in Las Vegas, you might want to consider Bryce and Zion National Parks in Utah; the Hoover Dam; the Grand Canyon; and Sedona, Arizona. If you head up to Colorado through there, I'd recommend going towards Monument Valley, then Cortez and up towards Ouray, maybe to Denver if you have time, then loop back on I-70 and I-15 back to Vegas. Two weeks will give you plenty of time.