Phil,
If you are coming to Yellowstone in June I am sure all of the roads will be open but, as Helen said there will be construction. This is the URL for Yellowstone Road Conditions:
http://www.nps.gov/yell/planyourvisit/hours.htm
padredw,
Since the travel inside the park is so many miles to anywhere adding 60 miles to each day trip seems to be excessive. Island Park must be really special if you think it worth those extra miles. When we drove thru there the other day it was mostly covered in snow. We will have to revisit the area in the summer.
Note to all,
Grizzly RV Park has winter rates until the end of the month which are much better than the summer rates.
Grant