OK - yes it is geologically interesting and worth the walk from the Ranger Station ( do it with the guide though - they can tell you so much about the nature flora and fauna of the area). But...... be aware that in July and August it is incredible hot and at high altitude (over 7000 feet) it can be very tiring and strenuous. The best 'view' I found was at the top of the Postpile where the enormity of the basalt formations is quite a wonderful sight. Enjoy but take plenty of bottled water with you and walk slowly, take your time and take plenty of photos.
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