Historic Resource Study, Crater Lake National Park, Oregon, 1984
IX. Trails and Campgrounds of Crater Lake National Park
D. Other Trails
By 1912 there were several horse trails in the park–to Sun Creek, Mount Scott, Union Peak, and Bybee Creek, but they all were in need of improvement.  According to Superintendent Steel, there were no complete trails in the park by 1916, except that from Crater Lake level. 
Lodge to the lake By 1918 there were new trails to Garfield Peak, the first high point along the rim east of the lodge, and to The Watchman, while a trail to the summit of Union Peak, taking off from a point on the Medford Road a half mile west of park headquarters, was under construction and expected to be finished that season.  A year later hiking trails led to Union Peak and on to Bald Top, to Mount Scott, and to Garfield Peak, The Watchman, and Vidae Cliff. Trails were also built in 1919 from the rim road to Sun Notch and Crater Peak.  By 1927 thirty-eight miles of trail system existed within the park.
In 1930 work was progressing on a new trail to the top of Garfield Peak, where blasting had been necessary to break up huge rocks:
Where the old trail was narrow and steep and clung to the edge of the rim . . . the new trail dips and twists going upward in an even ascent. . . . Strong rock parapets have been built to insure safety. . They are built of the natural rock and cemented together and blend in with the rustic topography of the rim. 
This trail, which could also be used as a bridlepath, followed an entirely new route only occasionally cutting across the old path. Work continued on the Garfield Peak Trail in 1931. The length of the main trail was approximately 8,100 feet, with a rise of about 1,000 feet in elevation. Smaller foot paths were constructed at several prominent viewpoints. The trail afforded a number of magnificent views of the lake and extensive panoramic views from the peak of most of the park and surrounding country. A guided three-hour trip up the mountain was made each morning by a ranger-naturalist who explained rock formations and identified wildflowers.
The six-foot-wide Victor Rock Trail, approximately 220 feet long, connecting the rim promenade with the Sinnott Memorial Building, was paved in 1931, the stone walls along the trail having been constructed during the previous year.  Also in 1931 the eight-foot-wide paved walk along the rim with side walks to various views, activities, and centers was built. That same year it was concluded that the expense of maintaining the crater wall trail was out of all proportion to the original cost. Slides and falling rocks were endangering visitors, and it was considered advisable to relocate and reconstruct it. 
A new trail to the recently-completed Watchman lookout station was finished in 1932, of the same standard of construction as the Garfield Peak Trail. It was based on the 1931 rough trail used to get construction materials for the tower up the mountain. Half a mile long, five feet wide, with a grade of 15%, it afforded views of the western portion of the park and of the upper Rogue River valley. Another new trail, to Discovery Point, began at the west end of the rim promenade and extended northwest to the observation point. It was 4,280 feet long and very scenic, following the edge of the rim.