During one of the longest ski seasons in California’s history, Mammoth Mountain is getting ready to say goodbye to skiers and snowboarders who’ve been relishing their time on the slopes deep into summer. The ski resort in Mammoth Lakes will be open daily for snow sports through Aug. 6. It chalked up a remarkable 270-day season after big winter snowfalls were helped by a late June snowstorm. Squaw Valley Resort overlooking Lake Tahoe in Olympic Valley, Calif., also had a long winter-into-summer run. It closed for the winter season July 15, marking its latest closing date in the resort’s history....