According to Google maps, if you live on the North Side, or near the loop, the best way to get to Big Marsh is: get on the LFP – Ride to the south side of Jackson park and get on Jeffery – ride South to 103rd – watch out for trucks – peel off on Stony Island and take it into the park. Anticipate about an hour and a half.
Alternatively, you can ride the South Chicago Metra to 83rd, then get to Jeffery and ride from there.
IMO: I'd ride the lake front until 100th, then go west to Jeffery from there. I've ridden to 100th many times (though I haven't gone west from there). It's low traffic and really, really pleasant. Lots of cool old industrial things to see too.
If you know a safer, faster, or more pleasant way to get to Big Marsh without a car, please post it on this thread!
Your lakefront to 100th would be my top choice.
Doing some combo of King Drive and Cottage Grove (dogleg at 95th) to eastbound 103rd to Stony Island also works - more direct, but you're dealing with buses and a lot more traffic, then a highway interchange between Cottage Grove and Stony Island. Lakefront to 100th is more pleasant for sure.
I do a ride regularly that you may want to consider. check this out. hopefully this helps.
That looks like a nice ride. I've ridden all those roads except 103rd. I thought it was a heavy trucking route. Is it hairy or just a typical Chicago road?
The route includes Western Ave. Doesn't look like a pleasant ride in my opinion.
I would NOT recommend the Western portion of that route under any circumstances. Too much truck traffic, bus traffic, speeding in the more open sections and generally hazardous conditions for bikes.
Except for the section between Cottage Grove and Torrence, 103rd is very rideable - a mix of commercial and residential. From Cottage Grove to Torrence, there can be a LOT of truck traffic. There's also a highway interchange, so staying safe around the ramp traffic requires some caution.
The bridge over the rail yard (Stony Island to Crandon tends to be fairly open most of the time. For this reason, speeding traffic is a real problem. The faster you can ride this section, the better.
Instead of Western, Vincennes to Summit to Halsted is much more rideable. The volume of traffic tends to be reasonable. There's a LOT less speeding than on Western. Most of it has uncrowded bike lanes from Summit (near 87th) all the way to the West Loop. The pavement conditions are generally better, too.