Help needed - local advice for riding in the Southwest mountains.

I am part of a group that are planning a 10 day ride from Vegas throughough the southwest back to Vegas from April 17 to 28 next spring. The problem I am having is icy roads or snow at higher elevations on the the route through Sherman pass, Grand Sequoia National Park, and the river road that runs north through the park.
I have Googled weather and other sources but nothing is better than advice from guys who live/travel there.
Help please?

@1olbull has ridden that area a lot I would expect him to be chiming in shortly