Things To Do on an eBike in Custer County
Custer County gives an eBike rider a rail trail with tunnels, a state park of granite and grassland, and a scenic highway that closes to cars each winter.
Both rental shops are on the eBike shops in Custer page. The rules here are stricter than elsewhere in South Dakota, so read the access notes for each route before you reserve a bike.
Where to ride in Custer County
Three corridors matter in Custer County: the Mickelson Trail, the multi-use trails of Custer State Park, and the park's tunnel highways.
Riding in Custer County, South Dakota.
The Mickelson Trail is a graded rail bed with gentle slopes, Custer State Park trails are shared hiking and horse trails with more rough ground, and Needles Highway is a paved mountain road with very narrow tunnels.
1. George S. Mickelson Trail through Custer
The state trail follows a former railroad grade through spruce and ponderosa pine and passes through the town of Custer. The Game, Fish and Parks page describes crushed limestone, more than 100 converted railroad bridges and 4 rock tunnels, with most of the trail at or below a 4 percent grade. The state trail brochure marks the trailheads by milepost.
Distance: 109 miles end to end, and the state brochure's mileposts put the Harbach Park trailhead in Custer at 44.5 and Hill City at 60.1, about 15.6 miles apart; start: Harbach Park Trailhead in Custer, milepost 44.5; a 3.2-mile spur on the brochure map runs toward Custer State Park; surface: Crushed limestone.
eBike access: Class 1 eBikes only, under SDCL 41-17-27 as amended in 2025, and a Class II or III rider risks a Class 2 misdemeanor. Etiquette and planning: Buy a $5 daily or $20 annual pass if you bring your own bike, stay to the right, yield to walkers, and never pass inside a tunnel. Managing source: South Dakota Game, Fish and Parks, Mickelson Trail policies.
2. Custer State Park bike trails
Only certain hiking trails in the park are open to bikes: Badger Clark, Barnes Canyon, Bison, Cairn, Creekside, Grace Coolidge and Prairie. The park describes these as shared with hikers and horse riders.
Distance: Not published by the managing source; start: Park trailheads; check the park's trail map for the one nearest your campsite or lodging; surface: Natural-surface park trail.
eBike access: The park pages do not name eBikes. Under SDCL 32-20B-12 a Class III is barred from non-highway paths unless the park expressly permits it, so confirm with the park before riding any class. Etiquette and planning: Pay attention to posted notices, because the park warns that bison are dangerous in every season, especially in spring when calves are present. Managing source: South Dakota Game, Fish and Parks, Custer State Park trails.
3. Needles Highway and Iron Mountain Road
Needles Highway is a 14-mile drive through ponderosa pine, birch and granite spires that closes to vehicles with the first snow and reopens around April 1 or later. While it is closed to motor vehicles the park says it is open to hiking, biking, snowshoeing and skiing. Iron Mountain Road is a 17-mile route with three tunnels and pigtail bridges.
Distance: 14 miles for Needles Highway and 17 miles for Iron Mountain Road; start: The park describes these as scenic drives; no single start point is published; surface: Paved mountain road.
eBike access: The page does not discuss eBikes, so treat each as a road where an eBike follows bicycle rules and check for closures first. Etiquette and planning: The Needles Eye tunnel is only 8 feet wide and the Iron Creek tunnel is 8 feet 9 inches wide, so dismount if traffic is present and use lights. Managing source: South Dakota Game, Fish and Parks, Custer State Park scenic drives.
4. Centennial Trail inside Custer State Park
The 111-mile Centennial Trail crosses the park for about 22 miles from Iron Creek in the north to French Creek in the south. The park notes that mountain bikers and horse riders share it with hikers.
Distance: About 22 miles inside the park; 111 miles overall; start: Iron Creek Trailhead, Badger Hole Trailhead or French Creek Trailhead; surface: Natural-surface singletrack.
eBike access: The Forest Service treats eBikes as motor vehicles, so on non-motorized trails they need a local designation, and we found none naming this trail, which makes it a no for eBikes unless a sign says otherwise. Etiquette and planning: Check the trail map and ask Custer State Park staff before you bring an eBike here. Managing source: South Dakota Game, Fish and Parks, Custer State Park trails.
Planning a Custer County ride
Rent in Custer and ride out and back along the Mickelson Trail. If you are renting in Hill City instead, Bicycles & Boats says its rental eBikes are Class 1 pedal assist, which is the class the trail allows, and that the trail pass is included.
Half-day and full-day eBike plans
Half day: Rent a Class 1 eBike in Custer, buy or confirm the trail pass, and ride a few miles along the Mickelson Trail before turning around.
Full day: Ride the Mickelson Trail in the morning, then drive into Custer State Park for the Wildlife Loop and walk the Needles area, since the park's bike trails do not name eBikes.
What not to ride
Class II and III on the Mickelson Trail: The trail is Class 1 only, and the penalty is a misdemeanor.
Centennial Trail on an eBike: It is a non-motorized singletrack, and no designation we found opens it to eBikes.
Needles Eye tunnel in traffic: At 8 feet wide it cannot safely hold a bike and a car side by side.
When to ride Custer County
Cooler months bring quieter trails around Custer, while midsummer rewards a dawn start and plenty of water.
Shop hubs
The directory lists one town, Custer. Details for each business are one click away on the town page.
Rental and tour operators
Rental listings follow. A card cannot show which bikes are free, so ask about electric models and helmets.
South Dakota eBike rules snapshot
South Dakota sorts eBikes into three classes in SDCL § 32-20B-9. An electric bicycle is a bicycle or tricycle with a seat or saddle, operable pedals for propulsion, and an electric motor of 750 watts or less. A Class I motor assists only while you pedal and stops assisting at 20 miles an hour. A Class II motor can propel the bike without pedaling and also stops at 20. A Class III motor assists only while you pedal and stops at 28. Since 2020, § 32-20B-10 has required a permanent label showing class, top assisted speed, and motor wattage. Section 32-20B-11 says the motor must disengage when you stop pedaling or apply the brakes, wording that sits awkwardly beside the Class II definition. An electric bicycle is left out of the moped, motorcycle, and off-road vehicle definitions in § 32-20-1.
The path rule is § 32-20B-12. Unless the governmental entity in charge says otherwise, you may ride a Class I or Class II on any bicycle path or multi-use path. A Class III is barred from those paths unless the path is within or next to a roadway or the entity expressly permits it, though a Class III may use a natural-surface trail designated non-motorized if the entity has not restricted it. The George S. Mickelson Trail is stricter. A 2025 law, Chapter 178, amended § 41-17-27 so that only a Class I eBike may use the trail; Class II and Class III are not exempted, and a violation is a Class 2 misdemeanor. Under § 32-20B-13, a Class III operator must be at least 16, though a younger child may ride as a passenger on a Class III built for one. A Class III also needs a working speedometer.
A helmet is required only on a Class III, for operators under 18 and for every passenger of any age (§ 32-20B-14). We found no statewide helmet rule for Class I or II, no eBike driver license, no registration, and no insurance requirement. On the road, a rider going slower than traffic keeps as close as practicable to the right edge (§ 32-20B-5), and a rider on a sidewalk has a pedestrian's duties and must yield and signal before passing. Cities, state parks, and federal land add their own rules. Read our South Dakota eBike laws guide, then check the sign at the trailhead.
South Dakota Game, Fish and Parks manages the Mickelson Trail and Custer State Park trails, and its Mickelson Trail policy page lists electric wheelchairs and Class 1 eBikes as the motorized exceptions. State park pages we read for other areas do not mention eBikes, so ask the park before riding a state park trail.
Federal land follows different rules. The Forest Service manages eBikes as motor vehicles under its travel rules: all three classes are allowed on motorized trails and roads, and a non-motorized trail opens to eBikes only if the local forest designates it. National parks decide for themselves. Look up the specific unit before you load the bike.
In Custer County the Mickelson Trail rule is the one to remember. South Dakota's general path rule lets Class I and II eBikes use bicycle and multi-use paths, but the 2025 law that amended section 41-17-27 allows only Class I on that trail.
Frequently asked questions
How long is the Mickelson Trail?
The state page says 109 miles, from Edgemont to Deadwood.
How many Mickelson trailheads are there?
The state page says 14 trailheads in one sentence and lists 15 in the park specifications, so ask the trail office at 605-584-3896.
Can I ride a Class 2 eBike on the Mickelson Trail?
No. Only a Class I eBike is exempt from the motorized vehicle ban, and a violation is a Class 2 misdemeanor.
How wide are the Needles Highway tunnels?
The park lists the Needles Eye tunnel at 8 feet wide and the Iron Creek tunnel at 8 feet 9 inches wide.
Is the Mickelson Trail open at night?
No. The policy page says the trail is closed from half an hour after sunset to half an hour before sunrise.
Does a minor have to wear a helmet on an eBike in South Dakota?
On a Class III, yes. Section 32-20B-14 covers operators under 18, and a Class III also requires an operator at least 16 years old under § 32-20B-13. We found no statewide helmet rule for minors on Class I or II. See the South Dakota eBike laws guide.
Does a South Dakota eBike need a license or registration?
We found no license, registration, title, plate, or insurance requirement for an electric bicycle. Section 32-20-1 leaves electric bicycles, as defined in § 32-20B-9, out of its moped, motorcycle, and off-road vehicle definitions.
All shops in Custer County
The county directory, 2 listings in 1 city, lives on the Custer County eBike shops page.