From this ride 03/31/2010 Route in St Charles, MO, United States | MapMyRide it looks like there is 100' rise going up the bridge and another 100' gain on the east side of the park - which isn't shown in the profile posted by njkayaker. The ride posted was 20 mi and 587 ft. with two laps around the park, one in each direction. Looks like 853' is not out of realm of possibility in that area if there is actually 100' elevation gain on the east side of the lake. Is there?

I'm just interested in looking at mapmyride, google bike routes, etc. Haven't looked at these in a while and its fun to see improvements made.