I recently utilized the Hardesty/Mt June loop for a conditioning hike. As Brian has stated, it can be made into a 18 mile hike are trail run with a minumum of 4,000 ft of elevation gain. There are interesting rock formations on MT June as well as eagles rest not more than a few miles to the west. Great area to explore.
Headed down to do some Eugene-area peakbagging and tick off June and Hardesty. Made it up to June in under an hour and enjoyed views and sunny warmth. Headed over then to Hardesty , nailed that, and on the way back, ran into a mother black bear and her cub on the west side of the meadow. They had seen or heard me and within a few seconds wandered into the woods although it was near where I had to go on the return trail. I did a lot of yelling and singing and banging of trekking poles on the way back. Fun area.