Specifically for Elk: remove as much fat as possible because the flavor is strong.
For general roasting:
I use a two step process. I sear the meat at 450 F for 10 minutes, then turn the oven down to 250 F and cook until my thermometer reads 125-130 F. It heats a little more while I wait to carve. I really like my thermometer with a monitor and probe. I just set the alarm for 125 and wait.
I season with salt and pepper only.
Joy of Cooking agrees with me and suggests the hi-low method for all antlered game animals.