Here's some notes from the Park Ranger-Mike Bowman regarding access.

Name: Michael Bowman
Email Address: mibowman@state.pa.us
Date: 11/27/2008
Please forward to appropriate person: Just to inform you that Ricketts Glen State Park is updating the Lake Rose trailhead and road. Construction has started and will take place all winter, and the Lake Rose Trailhead, plus the parking at the maintenance buildings will be closed all winter. For ice climbing access and parking info, please contact the park, at 570-477-5675 before bringing a group. As of now,(11-27-08) we do not have a solid plan on registration/access. Mike Bowman DCNR Ranger Ricketts Glen State Park

and a follow up message on 11/28:

As of now, we do not even have a system set up for registration. There are two options for entering the trail (for people with crampons)- Lake Leigh side, starting at the Beach Lot #2 and walking across the Highland Trail, or starting out on Rt. 487 walking in on the Old Beaver Dam Road. Either one is fine, but we have to set up some form of registration so that we know what vehicles are doing in the park after sunset. the Old Beaver Dam Road (or better yet the longer, Ganoga View Trail) would be better for cross country skiing into the falls to climb if you plan to do this.
You could call the week before you come, Monday through Friday, 8am to 4pm (current office hours). You could also email me.
But, as soon as I the manager works out the ice climber registration details, I will let you know.
Mike

I will post more info here as I know more.


General Overview
Ricketts Glen SP is about 40 minutes north of BU, and offers opportunities for ice climbing at its main waterfall. It takes approx. 45 minutes to hike in to the location, which is set up like an ampitheater. There are varying degrees of difficulty for climbs.

The main office # is (570) 477-5675.
The park’s website is www.dcnr.state.pa.us/stateparks/parks/rickettsglen.aspx, where ice conditions are posted.

At the parking lot for the trailhead there is a building with public restrooms and a sign-in book for climbers.
Other groups will be out, so respect their climbing experience by concentrating Quest groups on a few climbs, and not hog the entire area. The climbs on the left side of the ampitheater work best.

Directions:
Road conditions may vary, call ahead to check.
1. From Bloomsburg drive North on Rt. 487 to Rt. 118.
2. Make left on Red Rock Mtn. Road and drive West. Sign for Ricketts Glen SP on right. Turn right.
3. Follow SP road North. Will pass new park office. Park by gate across dirt road at end of parking lot. Alt. parking at 118, then hike up.
4. Hike on road to trail sign, continue on Falls Trail. At trail junction make a right. Will eventually cross a wooden bridge, afterwards make a left. Will soon encounter first waterfall. Total distance to the climbing site is less than 1
mile.

If the road conditions are poor yuo can also park at the bottom of Red Rock Mountain in a state park parking lot and walk up to the falls from below.

Safety Considerations
1. Participants should have ice axes, crampons, and helmets on at the first waterfall before continuing down the trail, as there are numerous places to slip and fall. Harnesses should be put on at the parking lot.
2. While at the climbing site participants may get cold, or accidentally step into the stream. Everyone should be dressed for the weather, and staff should have extra pads, sleeping bag, stove, and pot to make hot drinks and treat hypothermia.
3. Nearest hospital is Bloomsburg Hospital (570) 387-2100. 911 service is available.
4. Watch out for ice fall; everyone must be wearing a helmet! Crampons must stay on until the end of the day.
5. Only climb on solid ice formations, could destroy forming ice. Do not climb on unattached pillars.


From Wikipedia:

The park contains the Glens Natural Area, a National Natural Landmark; the Falls Trail passes twenty-four named waterfalls, the highest being 94feet (28.7m) Ganoga Falls. Ricketts Glen State Park is one of twenty-one chosen by the Pennsylvania Bureau of Parks for its "Twenty Must-See Pennsylvania State Parks" list.

History

Robert Bruce Ricketts was a veteran of the American Civil War. Colonel Ricketts at one time owned outright or controlled over 80,000acres (323.75km²) of land in this area. His heirs, through the Central Penn Lumber Company, sold 48,000acres (194.25km²) to the Pennsylvania Game Commission from 1920-24. This left them with over 12,000acres (48.56km²) surrounding the Ganoga Lake, Lake Jean and Glens area.
Ricketts and the other settlers living in the area were not aware of the glens and their many waterfalls until the 1890s. At that time, a house guest of the Ricketts went fishing and wandered down Kitchen Creek, discovering the many waterfalls and the reason why no fish came up the stream.
Although the area was approved as a national park site in the 1930s, World War II brought an end to this plan for development and in 1942 the heirs sold 1,261acres (5.10km²), the Falls and Glens area, to the Commonwealth of Pennsylvania for a state park. Additional purchases eventually brought the park to its present size. Recreational facilities first opened in 1944.

The Glens Natural Area

The Glens Natural Area, a registered National Natural Landmark since October 12, 1969, is the main scenic attraction in the park. Among giant pines, hemlocks, and oaks, two branches of Kitchen Creek cut through the deep gorges of Ganoga Glen and Glen Leigh and unite at "Waters Meet"; then flow through Ricketts Glen. Many of the magnificent trees in this area are over 500 years old, and ring counts on fallen trees have revealed ages as high as 900 years. Diameters of almost 4feet (1.2m) are common, and many trees tower to 100feet (30m) in height. The area is the meeting ground of the southern and northern hardwood types, creating an extensive variety of trees. In 1993, the Glens Natural Area became a State Park Natural Area and will be protected and maintained in a natural state.[2] A series of trails, covering a total of 5miles (8km) parallels the streams as they course down the Glens. Glen Leigh features eight waterfalls. Ganoga Glen has ten named falls, including the 94-foot (29m) Ganoga Fall, plus another good-sized unnamed waterfall on a side tributary. Ricketts Glen has three waterfalls just below Waters Meet, and two more 2miles (3km) farther downstream at PA route 118. One of these two, Kitchen Creek Fall, is directly below the highway bridge, which obscures much of the view. The farthest downstream, Adams Fall, is one of the most scenic falls in the park, and is just 0.1miles (0.2km) south of Pennsylvania Route 118, via an easy stroll along a trail from the parking lot.
Hiking the entire Glens area beginning and ending at PA 118 yields a 7miles (11km) hike that includes the Highland Trail. For a shorter hike, one may park at Lake Rose, near the junction of Ganoga Glen and the Highland Trail. It is possible to see all of the waterfalls except the two near the highway by hiking around the triangular area: Highland Trail / Glen Leigh / Ganoga Glen. The distance around the triangle is 3miles (5km). An optional side trip from Waters Meet along the three falls in the top of Ricketts Glen, then back to Waters Meet, adds 0.5miles (0.8km).