Currently, both passes are in decent shape for a passenger car with stiff suspension to make it BUT the last 7 miles are very bad. I am not sure how a passenger car can make it without hitting undercarriage.
Washboard has already come back after the roads got graded. There are laser sharp rocks waiting to puncture your tires. Airing down helps with washboard, deep sand and rocks but leaves side walls vulnerable to cuts.
Side wall punctures are not repairable.
Also, significant airing down makes street tires "chewy" on the inside reducing the life. Having exited on a donut tire and on a hose wrapped around my wheel, I think it would be irresponsible to go there without 2 spare tires mounted on rims. The only tow company that has the right equipment to tow your car out in case it breaks down charges between $2,000 and $15,000 per tow. AAA does not come into Saline. So, be prepared, that's all I am trying to say.