Eastern Oregon is the eastern portion of Oregon which is arid and sparsely inhabited. Much of it is desert and semi-desert. It covers between a third and a half of the state's land area. There are several mountain ranges running through this area (ie: Blue Mountains) which rise up substantially from the surrounding plain and which are forested with stands of Ponderosa Pines and Larch.
This is a big area transversed by I-84 and numerous U.S. Highways. Most off-the-beaten-path attractions (which most are) must be accessed by the many scenic roads running through the high plains and mountains of the area. Private vehicle is practically the only way to travel in the area, but cycling could be enjoyable (and physically demanding) on many of the smaller highways.
U.S. Route 26 is located in the northern part of Eastern Oregon and runs from the coast to the Idaho border.
The three rivers that border Sherman County provide world class recreation. The Columbia River to the north provides world class wind surfing and kite sailing. The moderate wind speeds and large swells on the river can provide for some interesting viewing of these activities. On days when the wind is not blowing the wide river provides great water skiing and personal watercraft riding. Fishing is also popular on the Columbia. Depending on the time of year, the Columbia provides excellent walleye, sturgeon, steelhead, and salmon fishing.
To the west lies the wild Deschutes River. The Deschutes is famous for fly fishermen to test their luck at landing salmon, steelhead, and trout. It was once rumored that Tiger Woods even made the trip to test his luck. If fishing isn't exciting enough for you, then the white water rafting might be what you are after. The ever-changing rapids provide dangerous yet exciting fun. Even if you're car camping off the I-84, Deschutes State Park, east of The Dalles is a fine place to stay (especially in low season) and there are trails leading up the River for miles with opportunities for bird-watching.
The John Day River to the east provides steelhead fishing in the colder months and great bass fishing in the summer time. The lower John Day also allows for water skiing.
All of the many cities and small towns have at least some cafes and restaurants if you're not cooking for yourself.
Like other Oregonians, those in the vast East like their booze, but remember they may be a bit more conservative about it that those in the Willamette Valley (Portland, Eugene, etc.) and that you will have to go a bit further to get it. Most towns with more than 500 peope have at least one bar, usually two; the smaller outposts, such as Paulina, may have one, but don't stake your last dollar on it.
Unless you are in a larger Eastern Oregon town, count on a more limited selection than what is usually available elsewhere in the state and more beer-only establishments.
Eastern Oregon is very sparsely inhabited, especially in the southeast counties. Always make sure your vehicle is in good working order and that you carry extra fuel and food. Help can sometimes be a long way away and cell-phone services is spotty.
The high-desert environment is one of extremes: autumn and winter can bring harsh snowfalls, while daytime summer temperatures can easily reach ninety degrees or more with considerable drops at night. Of course, altitude variances compound the issue: it could be 80F and sunny June day in Burns (4147' / 1264 m) yet snowing on Steens Mountain (9733' / 2967 m) - a major regional attraction - some seventy miles away. Always check the weather conditions of where you are and where you are going frequently, and carry layers of clothing so that you can adapt to any sudden changes.
Yes, there are rattlesnakes. No, they won't hurt you if you don't bother them. Same goes with the rest of the wildlife, to which the same usual rules apply: don't feed them, don't approach them...just leave them alone.
Be aware of hunting season if you plan on tromping around by foot and dress accordingly.