While these operations were going on the Northern Pacific once more found it advisable to increase its indebtedness, and added a third mortgage of $12,000,000 to the first and second mortgages which already have been described. Of the issue $8,000,000 were at once taken by a syndicate, and the $4,000,000 remaining were early disposed of to the same parties. The mortgage was said to be for the purpose of completing new work and for paying the floating debt; it also assisted in the redemption and refunding of the dividend scrip which had been issued to preferred stockholders in 1883; and the payment of $3,073,321 of this in cash, besides the extension of $1,567,500 more, now took place. The extended scrip was to be payable in 1907, to bear 6 per cent, and to be redeemable on thirty days’ notice on any interest day on or after 1892; and up to January 1, 1893, holders had the option of converting it into third mortgage bonds.[569] The third mortgage itself required the consent of three-quarters of the preferred stockholders, but this there seems to have been little difficulty in securing. The years 1886–9 saw also a considerable extension of branch and other construction. It was a time of great general activity. In another place the large additions to the Atchison system have been described; at the same time the Union Pacific grew from a system of 5825.6 miles in 1886 to one of 6996 in 1889, adding over 1100 miles; the Chicago, Rock Island & Pacific increased from 1384.2 to 1592.7; the Chicago, Burlington & Quincy from 4036 to 5140.8; and the St. Paul, Minneapolis & Manitoba from 1509.4 to 3030.1. Meanwhile the Northern Pacific added 656.8 miles, or an average of 219 miles a year.[570] In the far Northwest the great tunnel through the Cascade Mountains was nearly completed by May, 1888; and by the end of the following year a continuous line of road was in operation from Ashland, Wisconsin, to Portland, Oregon, which was of particular service in view of the difficulties with the Oregon Railway & Navigation Company, and was the reason for the willingness of the Northern Pacific to surrender control of that connection.[571] In 1888, also, negotiations were carried on with the Canadian Government for an extension into Manitoba; and the same year the Cœur d’Alene Railroad & Navigation Company was purchased, comprising a steamship and narrow-gauge line in Northeastern Washington which extended through the mining region of the same name.[572] Generally speaking, the Northern Pacific retained its character as a single-track transcontinental route with but few branches. Where it did expand was on the east, where it reached Duluth, Ashland, Superior, St. Paul, and Minneapolis, and on the west, where it joined Wallula, Portland, and Tacoma. The principal other branches were the ones mentioned: namely, those to Winnipeg, and to the mining districts in Montana and Washington.