AllTrails
8.7
The most complete trail database in the US, and the reviews are recent enough to tell you whether a trail is muddy, closed, or busy this week.
Free tier is usable; the paid plan runs about $36 per year.

A rare car-free Midwest option
Minneapolis has light rail from the airport to downtown, one of the best urban bike networks in the country, and lakes you can circle on foot.
It is the clearest case in the Midwest for skipping the rental car entirely.
Flights
MSP connects to downtown by Blue Line light rail in about 25 minutes.
Train
The Empire Builder stops at Union Depot in St. Paul.
Bus
Intercity coaches serve Chicago and Milwaukee cheaply.

Flat, car-free, and connects four lakes and a creek.

Contemporary collection plus a free sculpture garden.

A 50 mile loop of connected parkways through the whole city.
Two full days covers the essentials and three lets you add a day trip or an outdoor morning without rushing.
Check the getting-around notes above first: in some cities transit and walking beat a rental car outright, and in others a car is the only practical option.
The tools and providers that fit the way this trip actually works.
8.7
The most complete trail database in the US, and the reviews are recent enough to tell you whether a trail is muddy, closed, or busy this week.
Free tier is usable; the paid plan runs about $36 per year.
Best used as a price check and a way to filter for genuinely refundable rates rather than as your only lodging search.
Varies by market; always compare against the hotel's direct rate.
Strongest for skip-the-line attraction tickets and half-day tours you would otherwise queue for.
Attraction tickets from about $25; half-day tours from about $70.