Our visit to the dunes was wonderful. It was an early September day, and the weather was cool but pleasant.
We had a picnic on the sand and the boys threw rocks and sticks in the water.
There were no other visitors that day, which made it especially peaceful.
One reason there may not have been visitors was that it was hard to get to! The dunes are more or less across the Snake River from Boyer park, just down the road a little bit from the Lower Granite Dam. After 9/11, restrictions on crossing the dam were put in place, so we went all the way around to Clarkston then back to the river. When we got there, we saw a sign stating the dam is open for crossing Monday through Friday. Before I go again, I would call the US Army Corps on the number that can be found on this website to verify crossing:
The fact that few people can go there has probably been good for the dunes. We had a friend with us who had been here long ago, and he said the dunes used to be much more trampled from the college kids going there to relax or have parties.
There is a parking area and an outhouse at the trail head. The trail to the beach is short (maybe a quarter mile) and our kids did it on their own just fine. There is no lifeguard on duty, and I would be leery of doing anything more than shallow wading in the water.
While you are there, I recommended a trip to the Lower Granite Dam. There is a fish ladder with a viewing room inside the Visitor Center. The viewing room is very cool (why did I not take any pictures?), though the presence of fish may depend on what time of year you are there (sorry, I know nothing about fish). There are also free hard hat tours of the dam for all ages, but you must wear close toed shoes, so we did not do it on this trip (flip-flops).