After conducting a research, it appears that the boat ramp named Cherokee Marsh - Carry In Access is located in the city of Madison, Wisconsin.

According to the Wisconsin Department of Natural Resources, Cherokee Marsh is a carry-in access site, meaning it does not have a designated boat ramp or dock. Instead, it is intended for small watercraft, such as canoes or kayaks, that can be launched from the shore.

Furthermore, the site is open year-round and is free of charge. It is located on Lake Mendota, which is one of the largest lakes in Wisconsin and is situated in Dane County.

The width of the access point is not specified, but it is important to note that it is only intended for small, non-motorized watercraft. According to the Wisconsin Department of Natural Resources, only canoes, kayaks, and other non-motorized boats are permitted on Cherokee Marsh.

Overall, Cherokee Marsh - Carry In Access is a small boat access point that services Lake Mendota in Wisconsin. It is designed for non-motorized watercraft and is open year-round.