You can do a Grid MORA by looking on your map. On the map the are blue numbers that tell you the higest object in that square and add 1000ft or more convient is a route MORA which is the highest object within 5NM either side on your route not forgetting the ends of your route, add 1000ft. Some people will tell you to add 300ft on top of that as any object that is less then 300ft is shown.