The Lake Sammamish Half Marathon takes runners along the smooth gravel trail that connects Marymoor Park in Redmond to Lake Sammamish State Park in Issaquah. So, who is running and what is your Goal? This is a flat race so can be good for a PR. However, keep in mind it is crowded and a narrow trail. So if you are looking for a PR, head up to the front of the race or you will be jogging pretty slow for the first mile or so.