The smoke is coming from the Ferguson Fire which has been effecting Yosemite NP lately.
from inciweb.nwgc.org
Ferguson Fire
Incident Type: Wildfire
Size: 49,619 Acres
Contained: 29%
https://inciweb.nwcg.gov/incident/5927/
"The fire is now 49,619 acres with 29% containment and 3,898 personnel that are currently engaged on the fire which include 282 engines, 46 water tenders, 16 helicopters, 92 crews, 5 masticators and 81 dozers. There has been 1 fatality and 7 injuries to date. 1 structure has been destroyed."

For the smoke outlook today:
https://inciweb.nwcg.gov/photos/CASNF/20...28-100117-0.pdf

Dale B. Dalrymple