Driving back into Winter

Our purpose in coming this far north is to visit our niece Sarah and her family, who live just South of Breckenridge. They live high in the mountains, where winter is still in full swing even at the end of April. Because of this we plan to leave the trailer at Alamosa and drive north with just the van to see them, stay for the weekend, then drive back down again, to continue our journey Westwards.
Travelling north from Alamosa we are still travelling through Volcano Country. The huge flat plain we are driving on is the Saguache Basin, part of the Rio Grande Rift Valley, a huge chunk of ground that has been made when the mountains to either side separated and opened up this wide crack in the ground, which is some 500 miles long and up to 50 miles wide. It is surrounded by mountains, much of which is igneous in origin and there are many calderas, volcanoes, igneous extrusions and exposed igneous intrusions. We have already talked about the huge lava flow at Carrizozo (Valley Of Fires), the revealed Basalt Intrusions of Heuco Tanks, the supervolcano of Valle Caldera and the Mount San Antonio volcano. Now we are driving on this great plain which is basically a giant outpouring of lava, ash and tuff (a combination of stuff thrown out of a volcano). Much of it comes from one supervolcano called the La Garita Caldera, which is to the west of
The La Garita Caldera was active about 40 million years ago. It has been named by geologists as the largest single pyrocalstic event (explosion and outpouring) so far identified.
Many may remember the eruption of Mt St Helen in 1980, which poured inches of ash onto the land for many miles. Its estimated volume of ash was 0.8 cubic miles. The La Garita Caldera is estimated to have put out 5000 cubic miles of materials, in one explosion. The only trouble is because of many other volcanic explosions the original caldera is not easily identifiable, the Valle Caldera is if you check it out on Google Earth.
Well against this backdrop of mountains we drove north, getting higher and higher, until we reached the snowline and Sarah's house.