Hastings, in the far SE corner of the Twin Cities Bike Map has a surprisingly robust set of bike trails, called the Veteran’s Home Bikeway. The trail starts just north of Lock and Dam #2, runs on top of the dike that creates the pool behind the locks, and follows the river around downtown Hastings. The trail heads inland along railroad tracks that skirt the eastern edge of downtown, then splits, with one trail leading to CP Adam Park and a second that follows the Vermillion River around the southern edge of town.
Hastings is separated enough from the metro area to be surrounded by farmland and gravel roads, but not far enough to avoid metro area traffic. Ninineger Rd (Hwy 42) is the best escape route out of town. It will take you to the very attractive Spring Lake Park, an excellent destination with a modern visitor center, picnic grounds, hiking paths and great views of Spring Lake (Mississippi River).Traffic is moderate to heavy depending on day of week and time of day.
Hwy 54, SE of Hastings is designated part of the multi-state Mississippi River Trail. This route is recommended for experienced riders only. Traffic is high and the road is narrow with no shoulder.
If you are looking for a 20-25 mile route near the metro area, I recommend visiting Hastings. Downtown has a mix of bars, coffee shops and restaurants for post ride food and drink.