I don't but when you find out let us know!

Neskowin, on the beach.

One of the best camping trips I ever took with my daughters was to Wallowa Lake in NE Oregon... very close to the camping area is the Eagle Cap Wildernes Pack Station... www.eaglecapwildernesspackstation.com/

Please check out this site as they have rides available from 1 hr to a 5 day pack excursion... The people there are very, very nice and are some of the best in the business... Plus, you will see some of the most beautiful scenery in Oregon... the mountains there are referred to as "the North American Alps"... they are not volcanic mountains but "glacier cut" mountains. There is also a tram nearby that you can ride to the top of the mountains and you will feel like you are stepping right into a scene from The Sound of Music...

Oh.... over in Cannon Beach there is a small RV park and campground that has horseback riding on the beach... this was where I first introduced my daughters to riding... they were quite young... and the horses were quite gentle and the people nice... the campground was not much to mention as I remember...

www.cannon-beach.net/searanch/

www.cannon-beach.net/searanc...526.html

I'm pretty sure there is still an outfit in Longbeach, WA just north of Astoria about 15 min or so... planning on taking granddaughter this summer since I think they still have the childrens area where younger kids can get the exposure to riding...
The other thing to look into is people who board horses... depending on your experience and skill level. I've known many people who are simply looking for people to help them ride the horses they board so the horse can get the exercise they need. Check craigslist... there also use to be "horsemanship summer camps" check the Welches, Wemme and Sandy area.
Good luck!